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Ministry of Overseas Development
Notes on the Soils of Lesotho
by
D.M. Carroll and C.L. Bascomb
Technical Bulletin No. 1
Land Resources Division. Directorate of Overseas Surveys
Tolworth, Surrey,> England
1967
3)68
THE LAND RESOURCES DIVISION
OF THE
DIRECTORATE OF OVERSEAS SURVEYS
The Directorate of Overseas Surveys is the survey organization of the
British Government's Ministry of Overseas Development. It undertakes geodetic
surveys, topographical mapping and land resources investigations under the
British programme for Technical Assistance to developing countries.
The Land Resources Division of the Directorate
the assessment of land resources, and the making of
development and use. It works within the fields of
soil science, plant ecology, climatology, hydrology
and forestry.
undertakes or assists with
recommendations for their
geology, geomorphology,
and irrigation, agriculture
The reproduction of this report for international distribution and
scientific exchange has been approved by the Overseas Government concerned.
11
CONTENTS
Page
PREFACE
v
ABSTRACT
vi
PART I
- INTRODUCTION
1
Team composition
Procedure
Acknowledgements
PART II
1
1
2
- FACTORS AFFECTING SOIL FORMATION
Geology
Geomorphology
Climate
Vegetation
3
4
6
7
PART III - THE SOILS OF LESOTHO
8
Raw mineral soils
Weakly developed soils
Calcimorphic soils
Vertisols and similar soils
Claypan (highveld pseudopodsolic) soils
Brown soils of semi-arid regions
Eutrophic brown soils
Fersiallitic soils
Ferrallitic soils
PART IV
- THE SOIL MAP
APPENDIX I
APPENDIX II
3
9
9
10
11
14
16
17
17
19
21
- SOIL PROFILE DESCRIPTIONS AND ANALYSES
25
Methods of analysis
66
- X-RAY ANALYSIS DATA
69
APPENDIX III - AREAS OF THE DIFFERENT SOIL MAPPING UNITS
71
REFERENCES AND RELEVANT WORKS
73
MAP
- 1/1,000,000
SCALE RELIEF MAP (facing page 4)
MAP
- 1/250,000
SCALE PROVISIONAL SOIL MAP (in pocket inside
back cover)
(80714)
iii
PREFACE
The information presented in this bulletin was collected by
D. M. Carroll during a sixteen month tour in Lesotho from
January 1964 to May 1965. He was then a member of the Overseas
Pool of Soil Scientists of the Ministry of Overseas Development,
seconded to the Government of Basutoland (now Lesotho) under the
Special Commonwealth African Assistance Plan. In this period
semi-detailed surveys of selected development areas for the
Lesotho Agricultural Department were carried out, as well as more
extensive field work for a land resources survey.
Since the completion of this survey, the Overseas Pool of
Soil Scientists has been amalgamated with the Land Resources
Division of the Directorate of Overseas Surveys, under whose
auspices the report and maps have been produced. The analytical
data were supplied by C. L. Bascomb, Soil Chemist of the Soil
Survey of England & Wales, at Rothamsted Experimental Station.
This bulletin submitted to the Lesotho government in
November 1966, is reproduced with their kind permission in the
Technical Bulletin series of the Land Resources Division,
Directorate of Overseas Surveys.
(80714)
v
ABSTRACT
This report presents soil information collected during a land resources
survey of Lesotho (Basutoland).
The influences of geology, geomorphology, climate and vegetation on soil
formation in Lesotho are discussed. The properties of Lesotho soils are
described and a provisional soil classification is suggested. The major
well developed soils of the lowlands are fersiallitic soils and claypan soils
found over pediplaned Karroo strata. Vertisols have developed over alluvium,
dolerite sills and in topographic depressions, while eutrophic brown soils
have developed over peneplained basalt in the foothills, and rendzinas over
steep basaltic mountain slopes. Twenty selected profile descriptions with
analytical data are presented as an appendix. A provisional soil map at
1/250,000 accompanies the report.
RESUME
On trouvera dans ce document diverses données pédologiques recueillies
au cours d'une étude portant sur les ressources naturelles de Lesotho
(Basutoland). Les auteurs décrivent les effets de certains facteurs
géographiques sur 1'evolution des sols de la region ainsi que les caractères
de ces sols, en proposant une classification provisoire. Dans les parties
basses du pays les principaux sols bien développés sont les suivants: sols
fersiallitiques et sols lessivés recouvrant des couches de röche de Karrou
formant pediment. Des vertisols se sont formes au-dessus des alluvions et
des filons doleritiques, ainsi que dans les depressions. Au-dessus des
basaltes formant pénéplaine parmi les contreforts des montagnes on trouve des
sols bruns eutrophes; et sur les pentes basaltiques abruptes il y a une
couche de rendzines. Un appendice contient vingt profus accompagnés de
données analytiques. Une carte pédologique au 1/250 000 est annexée au
document.
(80714)
vi
PART I - INTRODUCTION
Lesotho, previously known as Basutoland, forms an enclave within the
Republic of South Africa; it lies between latitudes 28° 35' and 30° 40' south,
and longitudes 27° 00' and 29° 30' east.
Some two-thirds of its 30,344
square kilometres (11,716 square miles) is mountainous and subject to a
rigorous winter climate.
The country's economy at the time of writing
depends on a livestock industry, subsistence agriculture, the earnings of
labour outside the territory and grants from the United Kingdom Government.
This technical bulletin describes the major soil types of Lesotho; it
accompanies a land resource study, 'The Land Resources of Lesotho' (Bawden
and Carroll, 1967) and presents the more detailed pedological information used
in the compilation of that report.
There is little previously published
information on the soils of Lesotho.
Van der Merwe (1941) and Venter (in
Staples and Hudson, 1938) briefly discussed some of the country's soils, and
the Lesotho Agricultural Department has produced a provisional classification
of the major soil types.
In this bulletin, the factors affecting the formation of soils in Lesotho
are outlined and the properties of each soil type described, both in a
generalized form and also by reference to representative profile descriptions,
and their corresponding analytical data.
These soil types are classified in
terms of the mapping units used for the 'Soil Map of Africa' (D'Hoore, 1964)
and their distribution is shown on a provisional soil map at 1/250,000 scale.
TEAM
COMPOSITION
The survey was carried out by D.M. Carroll, with the assistance of
I. Tennent, Land Use Planning Officer of the Lesotho Department of Agriculture,
during the investigation of the potentially irrigable soils.
The Soil
Conservation Service of the Department of Agriculture supplied labour, transport, stores and equipment as required.
PROCEDURE
Throughout the soil survey considerable use was made of vertical
panchromatic aerial photographs taken by the Aircraft Operating Company,
Johannesberg, partly in 1961 and the remainder in 1962.
Those of the
eastern and most mountainous part of the country are at a scale of 1/40,000,
the remainder being at a scale of 1/30,000.
The Directorate of Overseas
Surveys has produced a series of 1/50,000 scale contoured topographic maps
from earlier photography taken in 1962.
The soil survey, during which soil
boundaries were plotted on these maps, was carried out in three stages:
Stage I
Semi detailed surveys of potentially irrigable alluvial soils were made.
Provisional soil boundaries based on land form differences were drawn on the
1/30,000 air photographs.
The soils were examined in the field in inspection
pits and auger holes.
The soil boundaries, adjusted where necessary, were
transferred to the 1/50,000 maps.
(80714)
1
Stage II
Detailed surveys of two development areas, Mejemetlata and Thaba
Phatsoa covering about 103 square kilometres (40 square miles), were made.
Provisional soil boundaries based on differences in landform were marked
on the air photographs.
Special mosaics at 1/10,000 scale were
constructed for the survey by the Aircraft Operating Company, Johannesberg,
which were used as field documents.
Soil inspection pits and auger holes
were made in the main soil types distinguished, and the provisional soil
boundaries were checked in the field.
The results were compiled as two
overlays to the mosaics: a soil and land capability overlay, and a
development plan overlay, the latter being made in collaboration with the
Soil Conservation Officer.
Stage III
Reconnaissance soil survey of the remainder of Lesotho was the largest
part of the project.
It was based on a division of the country into landform units.
Those for the mountainous area were established on 1/50,000
topographic maps by M. G. Bawden of the Land Resources Division, Directorate
of Overseas Surveys and P. J. Beaven of the Tropical Section of the Road
Research Laboratory, based on a study of the air photographs (see Bawden
and Carroll, 1967).
The lowland landform units were established by
D. M. Carroll also by air photograph interpretation.
Field checking of
the landform unit boundaries and their adjustment as necessary, was
followed by an examination of the soil cover for the units by means of
inspection pits and auger holes.
Profile pits were described and sampled
for all the important landform units.
The distribution of the different
soil types and the associated landform units was plotted on 1/50,000 scale
maps.
The terminology and method of description of profiles was generally in
accordance with the procedure outlined by the Soil Survey staff of the
United States Department of Agriculture (1951) and as later modified by the
same authors (1960).
The soil maps resulting from these surveys were compiled by the
Directorate of Overseas Surveys into a territorial soil map at 1/250,000
scale which accompanies this bulletin.
The 1/50,000 scale maps of the potentially irrigable areas, the
1/50,000 scale landform unit - soil maps, as well as the 1/10,000 overlays
for the development areas can be consulted at the Soil Conservation Office
in Maseru, Lesotho.
ACKNOWLEDGEMENTS
The authors wish to thank the Soil Conservation Section of the Lesotho
Department of Agriculture for their help and the provision of ancillary
staff for fieldwork.
In addition, they are grateful to many Southern
African and British pedologists for much helpful discussion of pedological
problems.
The authors also thank their colleagues at the Directorate of
Overseas Surveys and Rothamsted Experimental Station for their aid at all
stages of the work.
(80714)
2
PART II - FACTORS AFFECTING SOIL FORMATION
GEOLOGY
The geological succession in Lesotho is relatively simple as all the
formations found there form part of the Beaufort and Stormberg series of the
Karroo system, which range in age from Triassic to Lower Jurassic (Table 1).
The lowest members of the succession are undisturbed sedimentary rocks, which
are capped by several thousand feet of basaltic lava.
Numerous dolerite
intrusions occur, both as dykes and large sills.
TABLE 1
The geological succession in Lesotho (Stockley, 1947)
Lower Jurassic
Drakensberg Beds
Cave Sandstone
Karroo
System
Stormberg
Series
Upper Triassic
to Rhaetic
Red Beds
Molteno Beds
Beaufort
Series
Triassic
Dolerite intrusions
Upper Beaufort Beds
Rhaetic and Lower Jurassic
The Upper Beaufort Beds are yellowish weak sandy shales with some
sandstones and reddish mudstones.
Illite is a common constituent of these
and other fine-grained Karroo rocks (Du Toit, 1954) and soils derived from
them contain inherited illite in their clay fraction.
The Molteno Beds mostly consist of coarse yellow felspathic sandstones
alternating with white arkosic grits; grey shales or mudstones also occur in
the southern part of the country.
Molteno sandstones are more compact than
those above and below them in the geological succession and appear to
weather more slowly.
The soils derived from Molteno sandstones have a much
higher content of medium and coarse sand than soils derived from other sandstones in Lesotho.
In some localities, Molteno sandstones are slightly
calcareous and weather to a stiff, brown calcareous clay.
The Red Beds are composed of red and brown felspathic sandstones and
sandy shales.
These are not weathering colours, but the true colour of the
rock, since ferric oxide was deposited simultaneously with the other rock forming components (Stockley, 1947); the resulting soils vary from 10 YR to
2.5 YR in hue and have a high chroma.
Truly red soils can form from Red
Beds material without being necessarily influenced by the weathering products
of dolerite.
Most Red Bed rocks are fine-grained and the texture of the
soils derived from them is dominated by the fine sand fraction.
The Cave Sandstone is a hard, massive and unbedded, fine-grained
aeolian sandstone with white or yellow colours.
It contains fresh mica and
felspar and weathers to a pale coloured clay-rich material.
Microcline is
the commonest felspar in Cave Sandstone and other Karroo rocks (Du Toit,
1954) and provides a primary source of potassium ions.
(80714)
3
Dolerite
occurs as dykes of all sizes or as thick and extensive sills
and inclined sheets.
This dark coloured, medium grained rock contains
plagioclase felspar, augite and much chloritic material, and iron ore minerals.
Biotite and olivine are common component minerals.
The Drakensberi
Beds consist of very uniform compact or amygdaloidal
basalt or olivine basalt lava flows, the outcrop of which covers the major
part of Lesotho above 1850 metres (6,000 feet).
The mineral compositions
and textures of the lavas are generally similar to those of the dolerites,
but the lavas often contain a high proportion of glassy material.
Tuff,
agglomerate, ash and tuffaceous sandstone horizons occur locally within the
basalt flows, but do not significantly affect soil formation.
GE0M0RPH0L0GY
(See relief map opposite)
Lesotho can be divided into two physiographic provinces; the lowlands
and the mountains.
The lowlands form part of the South African Highveld;
the mountains, known as the Malutis in Lesotho, form part of the great
Drakensberg range.
The mountain province can be further divided into a
foothill region and a mountain region.
(a) The Lowlands
The lowlands of Lesotho consist of a belt of sedimentary rocks, which
outcrop along the country's eastern border; the width of the belt varies
from three to fifty kilometres (two to thirty miles) and its elevation is
between 1,500 and 1,850 metres (5,000 to 6,000 feet) above sea level.
The
lowlands are a part of the 'African' surface described by King (1962).
In the extreme west of Lesotho, there are extensive plains, underlain by
Beaufort and Molteno rocks, with a general elevation of about 1,500 metres
(5,000 feet); they are composed of broad, coalescing pediments, which merge
smoothly into convex senile interfluves.
These plains seem to represent a
more recent base-level, which erosional processes now operating are cutting.
The broken and hilly topography of much of the Molteno and Red Beds outcrop
has been produced by headward stream erosion and slope retreat.
The result
of this dissection is a pattern of slightly concave pediments passing up slope
into spurred interfluves with broad, gently sloping convex crests.
Soil formation in the lowlands is only indirectly related to the underlying bedrock because both slope crests and pediments are covered by mantles
of colluvially re-worked material.
It is now generally believed that during
the Quaternary era, Africa had its own palaeoclimatic sequence (D'Hoore, 1964)
and it seems likely that the thick mantles covering pediment slopes today were
formed by long periods of intense erosion during a pluvial stage of an
interglacial period, followed by gentle colluviation and accretion.
Sediments of this kind, termed 'pedisediments' by South African pedologists
cover large areas of the lowlands to depths of over 20 metres (60 feet).
The
material is well stratified and is mainly composed of a greyish calcareous
clay.
It is usually overlain by more recent sandy sheetwash or creep
deposits, and because of the morphology of this composite profile, it has
been called 'pseudopodsolic' by some pedologists.
The pedisediment is now
being eroded into deep gullies (dongas) which may represent the sites of old
buried drainage channels.
(80714)
4
D.O.S. (Misc)4l7A
©
LESOTHO GOVERNMENT 1967
Drawn, photographed and prepared for colour printing
by the Directorate of Overseas Surveys, 1966.
Printed for D.O.S. by the Ordnance Survey.
1800/4/67/3494/05
Many other lowland soils do not have a residual origin, although a clear
transition from weathering rock to the soil's B horizon may sometimes be
observed.
There appears to have been considerable reworking of soils overlying the crests and upper parts of slopes; the many stone-lines and bands of
rounded grit encountered, indicate that soil creep and other colluvial
processes are active even on very gentle slopes.
Interfluve crests are
usually occupied by fersiallitic soils without marked horizon differentiation;
their common boundary with the 'pseudopodsolic' soils is the landform boundary
separating slope crest and pediment.
The outcrop of numerous doleritic intrusions greatly modifies the lowland
landscape.
Narrow dykes form hummocky ridges extending for many miles; the
soils over the dykes are shallow and stony.
Thick sills rise a thousand feet
above the surrounding plains in the extreme west of the lowlands; the broad
pediment slopes at the foot of these sills are covered by dark clays.
There are two different kinds of alluvial deposit within Lesotho.
In
the first kind, both flat and inclined terraces are found along stream
courses and small rivers, where fine textured alluvium from mountain sources
is deposited; this material gives rise to a dark heavy clay soil.
The
second kind is of deep, weakly stratified sandy alluvium occurring along the
Caledon River, a major tributary of the Orange River.
Here the alluvial
material from basaltic sources is greatly diluted by sandy material from the
outcrops of sedimentary rocks surrounding these terraces; the resulting soils
are mostly only coarse or medium textured and their distribution pattern is
complex.
(b)
The Foothills
A conspicuous escarpment marks the eastern boundary of the lowlands; it
is virtually unbroken in a north-west to south-east direction and is as high
as 300 metres (1,000 feet) in places.
This escarpment is composed of rocks
of the Red Beds capped by the harder Cave Sandstone which above the escarpment forms plateaux or structural platforms with a general elevation of 1,850
metres (6,000 feet).
Isolated remnants of these plateaux occur as steepsided inselbergs throughout the lowlands.
Many of these plateaux have been covered by vast outpourings of the
Drakensberg lavas.
The region known as the 'foothills' in Lesotho comprises
both the gently sloping pediments at the base of the mountains and the
sandstone plateaux themselves.
The soils overlying Cave Sandstone are
yellow brown and coarse to medium textured and those of the pediment slopes
are red friable clays.
Both groups of soils appear to be reworked and
contain stone lines.
(c) The Mountains
The basaltic mountains cover over two-thirds of Lesotho, mostly as a
montonous sequence of steep ridges and deep valleys.
The general steepness
of these slopes allows only poor profile development in the soils of the
mountains, and accounts for the widespread distribution of shallow, immature
soils.
Deep soils only occur where the topography is flat enough to permit
the accumulation of colluvial material.
Colluvial soils of this kind cover
flats in valley floors and the remnants of dissected valley floodplains,
which are now sited on montane spurs flanking the major rivers.
(80714)
5
The steep mountain slopes level off at about 2,800 metres (9,000 feet)
to an extensive rolling upland plateau; this plateau has been dated by Dixey
(1942) as late Jurassic and forms a major part of the Gondwana surface
described by King (1962).
Although the action of frost and ice promotes
rapid physical weathering of the basaltic rocks, there is little chemical
weathering at these high altitudes and wind and water remove most of the rock
debris before it can develop into soil.
CLIMATE
The climate of Lesotho ranges from semi-arid to humid.
The total annual
rainfall averages about 740 millimetres (29 inches) over the whole country and
varies from less than 500 millimetres (20 inches) a year in the valley of the
Orange River and 600 - 900 millimetres (25-35 inches) in the lowlands to over
1,000 millimetres (40 inches) in the mountains.
These amounts are
concentrated in the summer months from October to April and little rain falls
in the remainder of the year.
Both the annual totals and the seasonal
distribution of rainfall can vary greatly from year to year.
Much of the
total rainfall occurs as heavy thundershowers.
Snow covers the upper slopes
of the mountains for several months every year.
Relative humidity is highest
in the summer months, when its value ranges from 45% to 80% throughout the day.
The temperature in Lesotho varies from place to place according to
altitude and decreases with increasing elevation.
The mean temperature in
the lowlands during June is about 7°C (45°F) with average maxima and minima
of about 15°C and 0°C (59° and 32°F) respectively.
In January, the mean
temperatures are around 21°C (70°F) with average maxima and minima of 25°C
and 15°C (77° and 59°F).
Extreme temperatures as high as 37°C (98°F) and as
low as -10°C (14°F) have been reported.
Frost occurs throughout the winter
months and is a powerful agent of mechanical weathering.
The open pan
evaporation is probably over 1750 millimetres (70 inches) per annum in the
lowlands and less than 1250 millimetres (50 inches) in the mountains.
The mountainous nature of the country's topography greatly affects winds
and the moisture they carry.
Rain shadow effects are common in the major
river valleys of the mountains.
Strong winds in the dry season desiccate and
erode the soil.
The aspect of a mountain slope influences the amount of radiation and
wind-borne precipitation that it receives.
North-facing slopes have a
warmer climate than south-facing slopes; evaporation is more pronounced and
snow lies for shorter periods.
Under these conditions, the rates of oxidation and leaching are higher and the soils on these slopes are brown, friable
clays.
The dry and cold winter climate of Lesotho does not favour rapid chemical
weathering and the harsh winter climate of the upper mountains almost
completely inhibits soil development.
The intensity of leaching generally increases with increasing altitude,
although the black clays of the mountains are able to maintain their high
content of bases, because they are only slowly permeable and occur on steeply
sloping sites that quickly shed rainwater.
Soils derived from Cave Sandstone
at elevations of about 1850 metres (6,000 feet) have a lower base saturation
than the morphologically similar soils derived from similarly fine grained
sandstones in the lowlands at elevations of about 1500 metres (5,000 feet).
(80714)
6
VEGETATION
Lesotho is a grassland country and there is an almost complete absence of
natural tree growth.
These grasslands may be climax communities and Acocks
(1953) has suggested that conditions are too dry or too frosty to permit the
development of trees.
Other Southern African botanists, however, prefer to
regard such grasslands as fire sub-climax communities (Rattray, 1960).
A
sub-climax successional to shrub may occur at any altitude if the site is
sheltered enough.
Many years of veld fires and overgrazing have greatly influenced the
formation of the present vegetation, and the mismanagement of land has
encouraged the invasion of the grasslands by shrubs.
Much of the lowlands of Lesotho have been mapped as Cymbopoion - Themeda
grassveld (Acocks, 1953).
The most important component of this veld type is
Themeda triandra,
virtually pure stands of which may be found on soils derived
from dolerite.
Erairostis
and other hardy grasses replace Themeda in overgrazed areas.
Sour grasses become more numerous in the wetter northern
section of the lowlands and Acocks has described this area as a transitional
zone from Cymbopoion - Themeda grassveld to Highland Sourveld.
Remnants of
the Highland Sourveld itself occur in sheltered valleys below about 2,100
metres (7,000 feet) as a mixture of small evergreen shrubs and trees.
Most
of the grasslands of the foothills and the lower mountain slopes have been
included by Acocks in his Themeda - Festuca Alpine Veld type; Themeda
triandra
is still the dominant species.
On the highest mountain slopes,
above an elevation of about 2,600 metres (8,500 feet) short leaved and short
stemmed grasses of the Fescue type predominate.
Festuca spp. also occur at
lower elevations on colder and moister south-facing slopes.
The grass cover
of the mountain tops is sparse and much bare ground is exposed.
Although the natural vegetation of Lesotho is grassland, the surface
horizons of many lowland soils have low carbon contents even in the soil's
virgin state, and are usually structureless with high colour values.
Shallow
soils over dolerite or basalt usually have a higher organic matter content as
these materials provide a base-rich weathering environment, which stimulates
the growth of a thicker grass cover.
There is a dense mass of vigorous
roots in the black clays of the lower mountain slopes and the products of
decomposition of dead roots are easily absorbed by the soil's colloidal
complex with the result that a strong, stable granular structure is developed.
This grade of structure is chiefly associated with Themeda and is usually
lacking in areas where alpine grasses are dominant.
Grassland gives only limited protection against erosion, particularly as
much of the country's rainfall is of high intensity and is concentrated into
only a few months of the year.
In these conditions, it is not surprising
that the parent materials of many Lesotho soils are erosional mantles and not
weathering bedrock.
(80714)
7
PART III - THE SOILS OF LESOTHO
The most important soils of Lesotho, both agronomically and pedologically,
are described in this chapter.
No attempt has been made to erect a taxonomie
soils classification at this stage and it has been found convenient to describe
the country's soils in terms of the mapping units of the 'Soil Map of Africa'
(D'Hoore, 1964).
The general level of investigation was not detailed enough to permit the
mapping of soil series and most soils are included in sets. Sets are flexible
groupings of soils with like profiles; they can be broadly defined in terms of
a modal soil and variations from it (Taylor and Pohlen, 1962). The constituent
soils need not be geographically associated and are not necessarily of equal
taxonomie rank.
Each set has been given a geographical name after a locality
in which the set is commonly found.
The soil sets and other mapping units
used in Lesotho are shown in Table 2.
In the following sections, a broad definition of each soil mapping unit is
given, and the characteristic sites as well as morphological and chemical
profile properties of its constituent soil sets are discussed.
The raw
mineral soils and lithosols, however, are not described in detail as they are
of small pedological importance.
TABLE 2
Soil sets and mapping units
UNITS OF 'SOIL MAP OF AFRICA' OCCURRING IN LESOTHO
A
B
C
Raw mineral soils
Weakly developed
soils
Calcimorphic soils
LESOTHO
SOIL SET
Aa
Ac
Rocks rich in ferromagnesian minerals
Rocks, not differentiated
Ba
Bb
Bd
Bo
Lithosols on lava
Lithosols on rocks rich in
ferromagnesian minerals
Lithosols on sedimentary rocks
Juvenile soils on riverine alluvium
Ca
Rendzinas and brown calcareous soils
Mokhotlong
Da
Of lithomorphic origin
Phechela
E
F, G
J, K
A, B
D
Vertisols
Oj
Of topographic depressions
Semonkong
Thulo
Khabos
F
Claypan soils
(Hignveld pseudopods o lie)
Fa
Not differentiated
Maseru
G
Brown soils of
semi arid regions
Gb
H
Eutrophic brown soils
J
Fersiallitic soils
L
Ferrallitic soils
(80714)
SELECTED
PROFILES
(IN APPENDIX)
C, D
H
I
Sephula
L
Not differentiated
Mats'aba
M
Hb
On soils rich in ferromagnesian
minerals
Machache
N
Ja
On sandy parent material
Jd
Not differentiated
Lc
Dominant colour yellowish»
brown, not differentiated
8
-
-
Leribe
Berea
0. P
Thebe
R
Q
A
RAW MINERAL SOILS
This class of mapping unit includes both hard rocks and the coarse
detritus mainly formed by the processes of physical weathering.
These materials may be regarded as 'non-soil* since biological soil-forming processes are
almost completely lacking in them.
There are two divisions in Lesotho:
Aa ROCKS RICH IN FERROMAGNESIAN
MINERALS
This division describes the basaltic rocks exposed on the plateaux and
steep slopes of the mountains and doleritic rocks mainly occurring in the
lowlands.
Ac UNDIFFERENTIATED ROCKS
This division is composed of a variety of sedimentary rocks found in the
lowlands.
B
WEAKLY DEVELOPED SOILS
Weakly developed soils of two types occur in Lesotho: lithosols and
lithic soils; and juvenile soils on recent deposits.
The former, of which
there are three subdivisions have a low level of profile development, which is
reflected in very weak horizon differentiation.
They are stony and shallow,
with solid rock within 30 cm (12 in) of the surface.
The juvenile soils have
no clearly differentiated genetic horizons, which is mainly due to the brevity
of the soil forming period.
Only one subdivision of this category is found
in Lesotho.
Ba LITHOSOLS ON LAVA
Soil development is retarded on the steep basaltic mountain slopes.
Bb LITHOSOLS ON ROCKS RICH IN FERROMAGNESIAN
MINERALS
The poor development of these soils is caused by the slow weathering of
dolerite under the present climatic conditions of Lesotho, but may also be
the result of site steepness.
Bd LITHOSOLS ON UNDIFFERENTIATED ROCKS
These soils form over a variety of lowland sedimentary rocks.
These
parent rocks have only a low content of weatherable minerals and are subject
to strong erosional processes associated with the intense rainfall and marked
relief of the country; they can only form a mature soil under favourable
geomorphological conditions.
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Bo JUVENILE SOILS ON RIVERINE ALLUVIUM
Site: the distribution pattern of these soils is complex; they usually occur
as thin strips bordering the Caledon and Orange Rivers, sometimes in association with vertisols.
Morphology: these are coarse and medium textured soils with an AC profile.
There can be considerable variation in their morphology within quite a small
area.
Their thin surface horizon is usually much lighter in colour than
their friable, structureless, dark brown subsurface horizons.
They may have
an occasional layer of dark clay in their profile, but they are in general,
not well stratified.
Three local mapping units, covering soils of this kind were used in a
survey of the country's alluvial soils; the units were principally separated
on differences of soil texture:
1
Texture not finer than loamy fine sand;
colours throughout the profile.
often uniform
2
Texture not finer than fine sandy loam (profile A).
3
Texture not finer than friable fine sandy clay loam;
darker colours and some weak structural development
(profile B ) .
Chemical properties: soil reaction is neutral at the surface and becomes
slightly more alkaline with increasing depth.
The whole profile has a moderate to high exchangeable base content; although these soils have a relatively
low exchangeable potassium content, their base saturation is always very high.
The organic carbon percentage is low in the sandier soils, but increases with
increasing depth.
C
CALCIMORPHIC SOILS
Ca RENDZINAS AND BROWN CALCAREOUS SOILS
Definition: these are AC profile soils with thick, well structured dark surface horizons (mollic epipedons).
They are rich in clays with a 2:1 lattice
structure and have a high content of exchangeable bivalent cations.
Site: these soils form on steep basaltic mountain slopes under a cover of
alpine or semi-alpine grassland; the total annual rainfall of these areas
varies from 750 mm (30 in) to over 1,000 mm (40 in).
Variations within this
class are mostly caused by differences of aspect.
Rendzinas are found on
south facing slopes, which are cold, damp and snowbound for long periods.
Northern slopes are warmer and drier for much of the year; soils on these
slopes (profile T) are browner and more friable than the typical rendzina.
Mokhotlong set (profiles C, D)
Morphology: a very thin layer of dark grey brown loose loamy sand colluvium
usually overlies the A horizon, which consists of 30-40 cm (12-15 in) of
black, stony or gritty firm clay; this horizon has a strongly developed fine
or medium granular structure, and the soil mass is firmly bound by a network
of vigorous grass roots.
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The parent material is a layer of gritty sandy loam in shades of grey or
brown overlying solid basalt lava.
Chemical properties: the rendzinas of the lower mountain slopes have a
slightly acid to neutral reaction and a high organic matter content; X-ray
analysis shows their clay complexes to be dominated by montmorillonitic clay
minerals.
Values of cation exchange capacity and base status are high.
The
content of exchangeable calcium and magnesium is very high, but these soils
contain very little exchangeable sodium.
With increasing altitude, leaching increases and weathering decreases.
The soils of the upper mountain slopes are acid with only moderate base status.
D
VERTISOLS AND SIMILAR SOILS
Definition: these soils have an AC profile and a dark thick clayey surface
horizon.
Their structure is often prismatic or coarse blocky, although the
surface may have a finer structure produced by a self-mulching process.
Their permeability is slow and their internal drainage is poor.
Most profiles
show some of the effects of mechanical re-working such as dry season cracks
and slickensides, but gilgai micro-relief is not well developed in Lesotho.
The clay fraction of these soils is dominated by 2:1 lattice clays; cation
exchange capacities are high and they are highly base-saturated, mostly with
bivalent cations.
Da VERTISOLS OF LITHOMORPHIC ORIGIN
This unit has been divided into two sets:
(a) Phechela set (profile E)
Site: these soils mostly occur on gently sloping clay plains overlying and
adjadent to dolerite sills; they are partly of sedimentary origin and partly
formed from dolerite colluvia.
They are confined to the driest part of the
lowlands with a marked dry season and a mean annual rainfall of about
600 mm (24 in).
Morphology: these soils are weakly self-mulching and cracks to the base of
the A horizon are common.
The solum is usually shallow.
The A horizon consists of a thick black clay, with coarse blocky or
prismatic structure, often breaking to finer blocks.
Its consistence is firm
or hard and this horizon often contains some carbonate concretions or stones.
The C horizon is a greyish brown gritty and stony sandy clay loam or
even coarser material, often with an abrupt boundary to hard and only partially weathered dolerite.
There are abundant carbonate concretions and sometimes small black manganese shot in this horizon.
Chemical properties: the whole soil is strongly alkaline and almost completely base saturated.
The cation exchange capacity is very high and the
soil has a moderate organic carbon content.
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(b) Semonkong set (profiles F and G)
Site: these soils form from colluvial material of basaltic origin over level
areas in the foothills and mountains.
They are found in the foothills at
elevations of 1,850-2,000 metres (5,000-6,500 feet) along drainage lines and in
other low-lying areas; they pass upslope into eutrophic brown soils. They
occur in the mountains at elevations of about 2,450 metres (7,500 feet) and
cover either floodplains in the upper reaches of rivers or extensive flats;
they are usually associated with rendzinas.
Morphology: these are deep soils and bedrock is rarely seen in the profile.
They are self-mulching and deep cracks are common.
The A horizon consists of a black clay with a medium blocky structure;
prismatic structures also occur, but these usually break into blocks.
The
soil's consistence is firm or hard.
This horizon does not contain carbonate
concretions.
The C horizon is a clay in shades of grey or brown; it may be slightly
mottled.
It is compact, with massive structure.
Carbonate concretions or
segregations may sometimes be noted in this horizon.
Chemical properties: soils of this set in the foothills have a high cation
exchange capacity and percentage saturation; they are neutral at the surface
and become slightly alkaline with increasing depth.
Soils with similar morphology occurring in the mountains are less weathered
and more highly leached; they are slightly more acid and their percentage
saturation is lower.
Both types, however, have a moderate organic matter
content.
Dg VERTISOLS OF TOPOGRAPHIC
DEPRESSIONS
This unit has been divided into two sets:
(a) Thulo set (profile H)
Site: these soils may occur as relatively thin strips of bottomland along
drainage lines or over much wider areas on the gentle lower slopes of dissected
pediplains; their most extensive development is in the western and southern
lowlands.
These soils are formed from colluvial pedisediment in sites where
the leaching of silica and bases is retarded.
These vertisols grade upslope
into claypan soils; the details of a soil with intermediate properties are
given in Appendix I (profile U).
Morphology: the surface of these soils is usually crusty and there is little
tendency to self-mulching.
Cracks penetrate most of the A horizon and separate
it into roughly wedge-shaped prisms.
Slickensides are a common feature of these
soils.
The A horizon consists of up to 60 cm (2 feet) of black clay or fine sandy
clay with prismatic or coarse blocky structure.
The soil' is very hard when
dry and sticky and plastic when wet.
There is often some small black manganese
shot in this horizon.
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The parent material of these soils is pedisediment; it is usually a calcareous clay with greyish colours (5Y hue), which becomes paler with increasing depth.
There are often abundant calcareous concretions in this
horizon.
Chemical properties: these soils are slightly acid at the surface, but
become strongly alkaline in the C horizon, where high values for CaCO^
equivalent are found.
The cation exchange capacity and base saturation
values are high throughout the profile.
The soil has a moderate organic
matter content.
(b) Khabos set (profile I)
Site: most of these soils occur in the broad flood plains of major rivers
such as the Phuthiatsana; they are derived from fine-textured alluvium.
These soils are also found over alluvial terraces in valleys flanked by sandstone cliffs and are associated with coarse and medium textured alluvial soils
in a complex pattern.
They may also occur along drainage lines in small
stream catchments near to the mountains and it is often difficult to separate
these soils from those of the Thulo set.
Morphology: the variable morphology of these soils reflects the heterogeneous
nature of their parent materials.
The soils are often covered by a few
inches of brown sandy colluvial drift; ploughing causes the development of a
darker, finer topsoil.
The soil is only weakly self-mulching and tends to be crusty.
and slickensides are sometimes seen in their profiles.
Cracks
The A horizon is a black to very dark grey fine sandy clay with a coarse
blocky structure; its consistence is very hard or very firm.
There are no
carbonate concretions in this horizon.
The C horizon is grey brown or dark brown and these colours often become
paler with depth.
Although it is fine textured, the structure of this horizon is finer than that of the A horizon and its consistence is less extreme.
There are often some carbonate concretions in this horizon.
The units used to map vertisolic types in a semi-detailed survey of the
alluvial soils of Lesotho were separated on the properties of the A horizon.
The most common unit had properties similar to those described above, while
another had a similar colour and textural range, but differed in possessing
a finer structure and a more favourable consistence.
A poorly drained unit
was also recognised.
Chemical properties: these soils are often moderately acid at the surface,
but neutral or only slightly acid in the C horizon (profile I is atypical in
this respect).
Cation exchange capacity and percentage saturation values
are moderate in the A horizon and are somewhat higher in the C horizon.
Extractable sodium appears to be relatively low in this set.
These soils
have a moderate organic carbon content.
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F
CLAYPAN
SOILS
Fa NOT DIFFERENTIATED
Classification: this is the most extensive soil type in the lowlands of
Lesotho; it forms part of the widespread group of soils in Southern Africa
termed Highveld Pseudo-Podzolic soils and Sols Lessives by D'Hoore (1964)
and Highveld Prairie by Van der Merwe (1941).
Murdoch (1964) has suggested
that the geographical qualification is misleading as these soils are not
confined to the South African Highveld and in this report the simple term
'Claypan soil', used by de Villiers (1965) and other pedologists to describe
soils of this type in Natal, has been adopted.
These soils can also be described under great groups of the Alfisol order in the latest USDA soil
classification (Soil Survey Staff, 1960).
Definition: these are soils of the ABC type with a textural or argillic B
horizon.
There is a characteristically clear or abrupt boundary between the
structureless sandy A horizon and the clay-rich B horizon with well expressed
structure.
The saturation of the exchange complex exceeds 50 per cent.
Horizon A is acid and horizon B may be weakly alkaline.
Genesis: these soils appear to have developed from a parent material of
recent surface accumulations of sand and the underlying pedisediment.
The
lithological discontinuity is sharply defined and is often marked by a grit
line of rounded iron concretions, whose shape suggests a transported origin.
Both iron and lime concretions co-exist within the pedisediment, which is
calcareous, and lime concretions commonly form about a nucleus of an iron
concretion.
The A horizon is often found to overlie both solid sandstone and
the argillic B horizon of these claypan soils.
Vertical and lateral
part of the B horizon and
differences between A and
effect a rough sorting of
clay illuviation appears to be occurring in the upper
this process may also help to maintain the sharp
B horizons and the activity of the soil fauna may
material.
Further detailed studies, with mineralogical and particle-size determinations, are necessary to fully explain the genesis of this interesting and
important group of soils.
(a) Maseru Set (profiles J, K)
Site: these soils cover pediment slopes in the lowlands; these pediments
are covered with mantles of colluvially reworked material and the claypan
soils are formed from these mantle materials and not directly from the underlying bedrock.
The claypan soils occur in areas where the mean annual rainfall varies from 500-900 mm (20-35 in).
Morphology: the A horizon has a total thickness of 30-45 cm (12-18 in) in
non-eroding or non-accumulating sites.
The boundary to the B horizon is
usually abrupt and grit lines are not uncommon at the base of the A horizon;
a layer of pisolitic ferruginous grit over 30 cm thick can be seen in gullies
by the Mafeteng-Wepener road.
The A horizon is a brown (typically a dry colour of 10 YR 5/3) loamy fine
sand or fine sandy loam.
It is usually structureless, but forms coarse clods
when dry.
There may sometimes be a weak structural development in the top
few centimetres of the horizon, particularly under a permanent grass cover.
The horizon's consistence is loose or, more rarely, friable.
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An A2 horizon may sometimes be present. This is a thin, discontinous layer with higher colour values and lower chromas than the overlying Al horizon; it usually has some fine, faint yellowish mottles and spots
of pseudo gley.
The maximum accumulation of concretions generally occurs
in this horizon.
Temporary perched water tables occur in some of these
soils; they result from intermittent saturation of the surface horizon above
the impermeable B horizon.
The predominant matrix colour of the B horizon is greyish-brown,
(2.5 Y 5/2, moist is very common) often diffusely intermottled with yellowish
brown; it tends to increase in value with increasing depth.
Its texture is
usually a fine sandy clay.
Ped exteriors in the upper part of this horizon
often have darker coloured illuvial coatings of clay and possibly dispersed
organic matter.
The structure in the B horizon is moderate to strong medium
blocky or prismatic; columnar structure has occasionally been observed in
donga or drainage line exposures.
The consistence of the horizon is very hard
or very firm and it is only slowly permeable.
It contains iron and, rarely,
lime concretions.
The tops of the structural units are sometimes covered
with a dust of very fine quartz.
The C horizon consists of very hard and dry pedisediment, which has the
appearance of a relict gley.
It is yellowish brown or light grey and is
usually diffusely mottled.
The texture can be quite variable, but is mostly
clay-rich and the horizon is generally apedal.
Calcium carbonate occurs as
powdery segregations or as concretions; these concretions often enclose smaller
iron concretions and were probably formed when the pedisediment was an actively
gleyed material.
Thick carbonate concretionary deposits can be found in some
drainage lines.
Manganese occurs as black stains or as small soft concretions.
There may be several distinct layers in the pedisediment, which may attain a
depth of 20 metres (60 feet); it may have such features as grit or stone
lines, buried topsoils, and fossil root channels.
Chemical properties: the A horizon is usually moderately acid.
Its base
saturation is moderate and its cation exchange capacity is low; the quantities
of extractable cations are low.
The organic carbon content is low.
The soil
reaction of the B horizon varies from mildly to strongly alkaline.
The cation
exchange capacity is moderate to high and is very much greater than that of
the coarser-textured A horizon; percentage saturation values are high.
This
horizon has high extractable Mg and Na contents; the Ca/Mg ratio falls markedly from the A to the B horizons. The extractable sodium contents of some
soils of this set approach those of typical alkali soils; profile J has more
than 15 per cent exchangeable sodium.
The degree of alkalinity cannot be
correlated with changes in any morphological feature.
The organic carbon
figures sometimes show a secondary maximum in the B horizon.
The principal clay minerals of the A horizon of these soils have micaceous
structures; kandite minerals also occur in varying proportions.
The B and
C horizons appear also to contain mixed layer minerals.
(b) Sephula set (profile L)
Site: these soils cover the senile, weakly convex interfluves in areas of
pediplaned Molteno and Beaufort rocks; the rocks underlying the interfluve
crest are mostly sandstones or sandy shales.
The rainfall in these areas is
about 500-750 mm (20-30 in) a year.
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Morphology: these soils differ from those of the Maseru set in degree rather
than in kind.
Their A horizon closely resembles those of Maseru set soils,
but Sephula set soils do not have an A2 horizon and the boundary between the
A and B horizons is clear rather than abrupt.
The B horizons of the Sephula
set soils often have rather coarser textures and their colours have redder
hue and higher chromas than those of the Maseru set.
The parent material of
the Sephula set soils is pedisediment, which may be partly contaminated by
the weathering products of the underlying arenaceous rock.
Chemical properties: the A horizons of soils of this set closely resemble
those of the Maseru set soils in their chemical properties.
The proportion of
bases in the B horizon differs, however, and probably reflects the different
positions of the soils in the landscape; extractable K is high in the B horizons of the Sephula set, while the extractable Na content does not seem to
rise to the dangerous proportions of an alkali soil.
G
BROWN SOILS OF SEMI-ARID REGIONS
Gb UNDIFFERENTIATED SOILS
Mats'aba set (profile M)
Definition: these are reddish-brown soils, containing considerable reserves
of weatherable minerals, and appreciable quantities of clay minerals with a
2:1 lattice.
The base saturation of the B horizon is generally moderate.
Site: these soils are confined to dolerite outcrops under a rainfall of
625-875 mm (25-35 in) per annum; these outcrops are mostly sills or sheets
as most dykes are narrow and steep-sided and do not encourage soil accumulation.
The areas covered by these soils are small and cannot be adequately
represented on the 1:250,000 soil map.
Morphology: the A horizon is a dark red brown friable fine sandy loam with a
weak blocky or subangular blocky structure; this horizon is continually
replenished by new colluvial material and has a moderate content of weatherable
minerals.
The B horizon is red brown or even yellowish red, but does not have a hue
redder than 5 YR: it is a friable fine sandy clay loam with weak blocky
structure.
This horizon may be slightly stony or have some manganese concretions.
The lower part of the B horizon is sometimes a mixture of structures and the coarser peds are usually darker and firmer.
The C horizon is decomposing gritty material often enclosing spheroidal
dolerite boulders and overlying hard, but weathered rock; this horizon is
yellowish brown or brownish yellow and is speckled with white felspars and
black manganese stains.
Chemical properties: soil reaction throughout the profile is lightly acid.
The cation exchange capacity is low to moderate and the percentage saturation
moderate; both increase with increasing profile depth.
Organic carbon
values are low.
Profile M is more acid and base unsaturated than the modal
soils of this set.
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H
EUTROPHIC BROWN SOILS
H b ON SOILS RICH IN FERROMAGNESIAN
MINERALS Machache set (profile N)
Definition: these are permeable reddish-hued soils with clearly expressed
structure: they have an appreciable reserve of weathering_mat.pri aj_ and moderate cation exchange capacities and base saturations.
Site: these soils occur on pediment slopes at the foot of the basaltic mountains under a rainfall of 750-875 mm (30-35 in) per annum.
Morphology: horizons are not clearly defined in the profile of these soils
and their depth and stoniness is very variable.
Their fabric is earthy and
there are no clearly visible clay skins, although some peds take on a slight
gloss in the rainy season.
The A horizon is a dark brown friable clay loam with weak granular structure; its texture when estimated in the field is usually somewhat coarser than
the texture determined in the laboratory.
The B horizon is a friable clay with a weak fine to medium sub-angular
blocky structure; the upper portion of this horizon is usually reddish brown If
and the colour changes with increasing depth to yellowish red or red. Stone
lines and gravel accumulations can often be observed; rounded Fe Mn concretions increase in number towards the base of the B horizon.
There is usually
a clear boundary to weathering basaltic rock at the base of the profile.
Chemical properties: the pH of the A horizon is moderately acid (about 5.5)
and increases slightly with depth.
Cation exchange capacity, percentage
saturation and the exchangeable bases values are moderate.
The soil has a
moderate organic matter content.
The dominant clay minerals of these soils
are kandites, but thev also contain some micaceous minerals.
J
FERSIALLITIC SOILS
J a FERSIALLITIC SOILS ON SANDY PARENT MATERIALS
These soils have properties of both lithosols and fersiallitic soils; \
they cover relatively small areas of land and are of minor pedological or
agronomic importance.
Site: this type of soil is found over reduced interfluves developed from certain sandy Molteno rocks.
It occurs throughout the lowlands, but is most
common to the south of Mafeteng.
Morphology: the sandy nature of the local bedrock is clearly reflected in the
morphology of these soils; their texture is rarely finer than sandy loam and
there is only a slight increase in clay content with increasing profile depth.
Common colours are yellowish brown or brown and the whole soil is structureless
There is nearly always a sharp boundary to the underlying rock and the depth
of the soil is very variable.
Chemical properties: no chemical analyses have yet been made of this type of
soil, but its reaction is moderately to strongly acid and, because of its low
clay and organic matter contents, its cation exchange capacities and base contents are probably very low.
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Jd UNDIFFERENTIATED FERSIALLITIC SOILS
Definition: these are soils with an ABC profile and a relatively high content
of free sesquioxides.
The clay minerals are kandites, with lesser or greater
fl amounts of 2:1 lattice types; the Lesotho soils are not therefore truly
fersiallitic and probably represent an intergrade to brown soils of semi-arid
rpgjpns.
The cation exchange capacity of the whole soil is low and the base
saturation is commonly greater than 40 per cent.
Two important sub-divisions are recognized in Lesotho:
(a) Leribe set reddish brown soils (profiles O, P)
Site: these soils cover the crests and upper erosion slopes of spurred interfluves in some areas of Red Beds sandstone; they appear to be formed by the
colluvial reworking of the weathering products of sandstone and possibly
dolerite.
Morphology: all the soils in this set have a hue redder than 7.5 YR.
The
profile is deep and lacks clearly defined horizons.
The soil's fabric is
earthy and there are jio signs of easily recognizable clay skjns.
The A horizon consists of 25-40 cm (10-15 in) of red brown loamy fine
sand, which passes quickly to friable fine sandy loam; this horizon is virtually apedal, although some structure may develop in the surface rooting zone.
The B2 horizon is typically a red friable fine sandy clay loam; this
.1 material is commonly structureless, but with increasing profile depth, the
| soil's consistence becomes firmer and a weak blocky structure is developed.
The soil's parent material is a firm red clay, sometimes containing concretions,
which may merge into or stop abruptly at the underlying weathering sandstone.
Chemical properties: the A horizons of the Leribe set soils are strongly acid.
Values of the cation exchange capacity and the extractable cations are low,
except for those of extractable K, which are moderate.
The base saturation of
this horizon is usually a little greater than 40 per cent.
The organic carbon
content is usually less than 0.5 per cent.
Soil reaction commonly shows a secondary minimum in the upper part of the
B horizon, but increases again in its lower portions.
Cation exchange capacity
increases slightly in the B horizon and the extractable Mg content increases
while that of extractable K decreases.
The clay minerals of these soils consist of a mixture of illitic and
kandite types.
(b) Berea set yellowish brown soils (profile Q)
Site: these soils are found in areas of Red Beds and Molteno sandstones, where
they cover the crests and upper erosion slopes of spurred interfluves.
Some
are residual in origin and form, at least in part, from the underlying buff
coloured sandstones, while others are mostly formed from colluvial drift material also derived from these rocks.
The total annual rainfall of these areas
is about 625-750 mm (25-30 in).
Morphology: all the soils in this set have a hue as yellow as or yellower than
ii 7.5 YR.
The profile is rarely deeper than one metre (3 feet) and horizon
'I development is poor.
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The A horizon consists of 25-40 cm (10-15 in) of brown or yellowish brown
loamy fine sand, which is loose or friable and virtually apedal.
The B horizon is a yellowish brown or, more rarely, a strong brown friable
fine sandy loam or fine sandy clay loam.
A weak fine blocky structure can
sometimes be found in this horizon.
Rounded iron concretions become abundant L
towards the horizon base, sometimes forming a grit layer or an uncemented con- \
cretionary horizon.
The C horizon is commonly a yellowish brown fine sandy clay mottled with
variegated weathering colours; its consistence is firm and compact and it has
a medium blocky structure.
This material may merge into weathering sandstone which sometimes shows marked columnar structure, or there may be an
abrupt boundary between it and the sandstone.
Where the soil can be shown to be residual, the B horizon overlies a
yellowish gritty sandy loam which includes abundant fragments of weathering
sandstones; this material passes into a soft and friable yellowish brown sandstone, which merges through a harder and paler zone with bluish tinge into a
solid yellow sandstone.
Chemical properties: the A horizons of these soils are moderately acid
(pH 5.5-6.0).
Cation exchange capacity and extractable cation values are
low; percentage saturation is moderate.
The organic carbon content is
usually less than 0.5 per cent.
The pH range of the B horizons of the Berea set soils is similar to that
of their A horizons.
Cation exchange capacity is low and percentage saturation is moderate; extractable Mg increases slightly.
The clay fraction of the Berea set soils is dominated by micaceous
minerals, but a moderate amount of kandites are also present.
L
FERRALLITIC
SOILS
Lc NON DIFFERENTIATED FERRALLITIC SOILS, DOMINANT COLOUR YELLOWISH
BROWN
(
These are deep, virtually structureless soils, with poor horizon development.
Although they have a low base saturation, their cation exchange
capacities of about 30 meq per 100 g clay suggest that they have a higher
reserve of weatherable minerals than typical ferrallitic soils.
They can be
distinguished from the morphologically rather similar fersiallitic soils of
the Berea set by their pH values, which are about a unit lower.
Site: soils of this type cover gently undulating plateaux of Cave Sandstone
in the northern portion of the foothill zone, where the rainfall rises to
about 875 mm (35 in).
Thebe set (profile R)
Morphology: all the soils in this family have a hue of 7.5 YR or 10 YR.
The surface horizon usually consists of a shallow colluviallayer of humicstained brown loamy fine sand; it overlies about 40-50 cm (15-20 in) of a
loose and apedal horizon of brown fine sandy loam.
There is a gradual
i increase of clay content with increasing depth.
The subsoil is yellowish
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brown or strong brown; it is either structureless or has only minimal
structural development and its consistence is loose or friable.
Some rounded
iron concretions are usually found scattered throughout the sub-surface
horizons.
There is nearly always a sharp boundary between subsoil and the underlying bedrock, which is often weathered to a depth of several feet.
Chemical properties: these soils are very strongly acid throughout their
profile and their base saturation is extremely low.
Their organic carbon
content is over one per cent, which is considerably more than that of other
soils derived from sedimentary rocks in Lesotho.
(80714)
20
PART IV - THE SOIL MAP
This reconnaissance soil map is based on information collected during a
land resources survey of Lesotho (Bawden and Carroll, 1966).
The preliminary phase of this investigation consisted of a stereoscopic examination of
aerial photographs in conjunction with 1/50,000 maps, to recognize and define
differences in the landscape.
Elements of the landscape were selected,
within which a reasonably uniform distribution pattern of soils and vegetation
might be expected.
Typical elements were studied in detail in the field,
and the investigation later extended to cover the rest of the country in less
detail.
The units shown on the soil map were produced by combining similar landscape elements; the boundaries of each mapping unit therefore separate areas
that are both physiographically and pedologically distinct.
As more than
one soil type may be associated with any landscape element, the mapping units
are shown in the map legend as either simple units or as binary associations;
the predominant constituent of an association is placed first in the descriptions of the mapping units given below.
The names of the soil types, of
which the mapping unit is composed, have been chosen to match those names
used for the 'Soils Map of Africa' (D'Hoore, 1964); these soil types are described in detail in Part III.
THE MAPPING UNITS
1 Lithosols on lava
(Ba)
These shallow and stony soils occur on the higher mountain
slopes, where their development is limited by both steepness and a harsh climate.
2 Lithosols on lava/Basalt rock debris
(Ba/Aa)
This mapping unit covers much of the gently undulating
Upland Plateau, where much bare rock is exposed.
3 Lithosols on lava/Calcimorphic soils
(Ba/Ca)
These soils are found on many lower mountain slopes.
Calcimorphic soils develop on sites with relatively
gentle slopes or with an aspect favourable to the growth
of non-alpine grasses.
4 Lithosols on rocks rich in ferromagnesian minerals
(Bb)
This unit describes the shallow soils forming over steep
slopes on dolerite intrusions in the western lowlands.
5 Lithosols on rocks rich in ferromagnesian minerals/Eutrophic brown (Bb/Hb)
soils
These soils occur on the steeper slopes of the foothill
region.
The eutrophic brown soils are found on stable
or accumulative sites.
(80714)
21
6 Lithosols on sedimentary rocks/Sedimentary rock debris
(Bd/Ac)
The steep, rocky or eroded sites occupied by these soils
cover large areas of the lowland and Orange River regions.
7 Lithosols on sedimentary rocks/Fersiallitic soils
(Bd/Jd)
Soils of this mapping unit occur in the more broken
country of the lowland and Orange River regions. Deeper
soils of fersiallitic type are found as isolated pockets
within the unit.
8 Lithosols on sedimentary rocks/Ferrallitic Soils
(Bd/Lc)
This combination of soils is found on steep or eroded
land of the Berea Plateau.
Ferrallitic soils only occur
where site conditions favour the development of deep
soils.
9 Juvenile soils on recent riverine alluvium
(Bo)
These soils are confined to narrow terraces bordering the
two major rivers of Lesotho, the Orange and Caledon, and
some of their tributaries.
10 Calcimorphic soils/Lithosols on lava
(Ca/Ba)
This unit occurs on lower mountain slopes, often in
association with unit 3.
The gentler terrain of unit
10 however, ensures the predominance of calcimorphic
soils over the shallower and less well developed
lithosols.
11 Calcimorphic soils/Vertisols
(Ca/Da)
These soils can be found on very gently sloping sites
within the mountains.
Vertisols of the Semonkong set
form in positions where colluvial materials can
accumulate.
12 Vertisols of lithomorphic origin
(Da)
These soils are confined to clay plains overlying
doleritic intrusions in the western lowlands and constitute the Phechela set.
13 Vertisols of lithomorphic origin/Calcimorphic soils
(Da/Ca)
This unit is found on level sites within the mountains.
It differs from the similar unit 11 in its higher proportion of vertisols.
14 Vertisols of topographic depressions
These soils cover alluvial floodplains in the lowlands
(Khabos set) or may form the lowest number of a sequence
of soils on slopes developed from sedimentary rocks
(Thulo set).
(80714)
22
(Dj)
(Fa)
15 Claypan soils (Maseru set)
This unit describes the most extensive group of soils in
the lowlands, the soils of the Maseru set, which cover
dissected pediment slopes in the lowlands.
16 Claypan soils/Vertisols
(Fa/Dj)
These soils are found on very gentle slopes in the lowlands; vertisols of the Thulo set form on level ground
adjacent to drainage lines.
17 Claypan soils
(Fa)
This unit occurs most extensively in the western lowland
plains.
Claypan soils of the Maseru set cover the lower
slopes, and the senile interfluves are covered by soils
with less clearly defined claypan soil properties (the
Sephula set).
18 Claypan soils/Fersiallitic soils
(Fa/Jd)
This unit includes fersiallitic soils on some spurred
interfluves and some crests; these sites are too small to
be mapped separately and they have been grouped with
larger areas of dissected pediments overlain by claypan
soils.
19 Claypan soils (Sephula set)
(Fa)
These soils are confined to convex senile interfluves in
the plains of the western lowlands.
20 Claypan soils
(Fa)
Sephula set soils cover senile interfluves in the plains
of the western lowlands, but, for convenience in mapping,
this unit also includes small portions of the corresponding pediment slopes, which are overlain by Maseru set
soils.
21 Euthropic brown soils/Vertisols
(Hb/Da)
These soils form over the gentle slopes of the foothill
region.
The vertisols of the Semonkong set only occur
along drainage lines or on other low-lying sites.
22 Fersiallitic soils
(Jd)
Fersiallitic soils cover large areas of the lowlands;
they form over the crests and upper slopes of spurred
interfluves and isolated hills of sedimentary rocks.
Soils of the Leribe and Berea sets often occur in intimate association and could not be differentiated at this
scale of mapping.
(80714)
23
23 Fersiallitic soils/Lithosols
(Jd/Bd)
The soils of this unit are mostly of fersiallitic type,
but some shallow, stony or badly eroded soils also occur
in association with them and have been included in the
unit.
This combination of soils is most common in the
Orange River region, but it also occurs in drier parts of
the lowlands.
24 Fersiallitic soils/Claypan soils
(Jd/Fa)
In this unit, areas of claypan soils on upper pediment
slopes, which are too small to be mapped separately, have
been combined with adjoining more extensive areas of
fersiallitic soils; isolated examples of this unit occur
throughout the lowland and Orange River regions.
25 Fersiallitic-Lithosol intergrades
(Ja)
These soils, which have properties intermediate between
the fersiallitic soils and the lithosols, occur on
reduced interfluves of Molteno sandstone; they are found
throughout the lowlands.
26 Ferrallitic soils/Lithosols
(Lc/Bd)
Ferrallitic soils overlie Cave Sandstone in the northern
part of the foothill region.
They are found on relatively level and uneroded land; lithosols occur on
steeper or eroded land.
(80714)
24
APPENDIX I - SOIL PROFILE DESCRIPTIONS
AND ANALYSES
(80714)
25
PROFILE A
JUVENILE SOIL ON RIVERINE ALLUVIUM
LOCATION:
By Caledon River bank, on Agricultural Experimental
Station, Maseru.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Very slightly convex broad river levee.
PARENT MATERIAL:
Developed from riverine alluvium.
VEGETATION:
Poor grass at edge of ploughed land.
SOIL DRAINAGE:
Free, permeability rapid.
HORIZON
1
(80714)
DEPTH cm (in)
0 - 38 (0 - 15)
DESCRIPTION
Brown, 10 YR 5/3, dry (brown, 10 YR 4/3, moist)
loamy fine sand; structureless; loose consistence,
dry; slightly wavy, clear boundary to:
38 - 94 (15 » 37)
very dark greyish brown, 10 YR 3/2, moist; loamy
fine sand with lenses of finer material; very
weak medium blocky structure, breaking easily
into granules; friable consistence, moist;
slightly wavy, gradual boundary to:
94 - 191 (37 - 35)
plus
dark brown, 10 YR 3/3, moist, passing to brown
10 YR 4/3, at 115 cm; fine sand; structureless;
loose consistence, dry.
26
PROFILE A
HORIZON
1
2
DEPTH cm
3-15
43-54
1.40
2.10
Moisture 100-105°C %
.
.
2 0 0 M - 2 mm
%
7
6
50M - 2 0 0 M
%
73
63
20M
-
50M
%
9
10
2M
-
20M
%
3
6
<2M
%
7
13
CaCOg Equivalent %
nd
nd
Loss on Ignition %
8
3.2
Organic Carbon %
0.3
nd
Total Nitrogen %
0.04
nd
C/N Ratio
1.8
nd
pH in water (1:2.5)
6.3
7.1
pH in M/100 CaCl2
5.7
6.2
Exchangeable Calcium meq %
4.9
9.5
Exchangeable Magnesium meq %
2.3
4.8
Exchangeable Potassium meq %
0.19
0.14
Exchangeable Sodium meq %
0.10
0.13
Total Exchangeable Bases meq %
7.5
14.6
Exchangeable Hydrogen meq %
1.7
2.0
Cation Exchange Capacity meq % (by addition)
9.2
16.6
82
88
Base Saturation %
nd = no determination or no sample;
(80714)
27
tr = trace;
• = nil
PROFILE B
JUVENILE SOIL ON RIVERINE ALLUVIUM
LOCATION:
Close to river bank, by Phuthiatsana road bridge
Teyateyaneng district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Very gentle reverse slope of a river terrace.
PARENT MATERIAL:
Developed from riverine alluvium.
VEGETATION:
Poor grass at edge of ploughed land.
SOIL DRAINAGE:
Free, permeability moderately rapid.
HORIZON
DEPTH cm (in)
1
0 - 20 (0 -8)
20
(80714)
46 (8 - 18)
DESCRIPTION
Dark greyish brown, 10 YR 4/2, very slightly
moist; fine sandy loam; very weak fine blocky
structure; friable consistence, moist; smooth,
clear boundary to:
very dark brown, 10 YR 2/2, moist; fine sandy loam;
weak coarse blocky structure, breaking to medium
blocky; friable to firm consistence, moist;
smooth, gradual boundary to:
46 - 88 (18 - 35)
very dark brown, 10 YR 2/2, moist; fine sandy
clay loam; weak medium blocky structure; firm to
friable consistence, moist, slightly, plastic,
slightly sticky; consistence, wet; slightly wavy,
clear boundary to:
88 - 152 (35 - 60)
plus
dark yellowish brown, 10 YR 4/4, almost dry; fine
sand; structureless; loose consistence, dry.
28
PROFILE B
HORIZON
DEPTH
cm
Moisture 100-105°C %
1
2
3
0-15
25-38
64-76
3.54
3.48
4.28
4 '
5
6
52
51
2 0 0 M - 2 mm
%
50M - 2 0 0 M
%
20M
-
50M
%
13
2M
-
20M
%
8
14
3
<2M
%
18
20
17
CaCOo Equivalent %
tr
tr
-
Loss on Ignition %
4.6
4.7
5.2
Organic Carbon %
1.1
nd
nd
Total Nitrogen %
0.09
nd
nd
,12
nd
nd
54
C/N Ratio
6.
20
pH in water (1:2.5)
6.9
7.2
7.5
pH in M/100 CaCl2
6.2
6.4
6.7
11.2
13.0
15.5
Exchangeable Magnesium meq %
8.3
6.4
9.6
Exchangeable Potassium meq %
0.27
0.19
0.17
Exchangeable Sodium meq %
0.13
0.18
0.20
Exchangeable Calcium meq %
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
Base Saturation %
19.8
25.5
2.9
. 2.7
2.2
22.8
22.5
27.7
88
87
nd = no determination or no sample;
(80714)
19.9
29
tr = trace;
- - nil
92
PROFILE C
CALCIMORPHIC SOIL, MOKHOTLONG SET
LOCATION:
Above Bushman Pass, Mountain Road, about 2250 m (7,500
feet) elevation.
CLIMATE:
About 875 mm (35 in) annual rainfall.
SITE:
Slightly convex slope (about 11°) southern aspect.
PARENT MATERIAL:
Developed from basaltic lava.
VEGETATION:
Poor Themeda veld.
SOIL DRAINAGE:
Free, permeability moderately slow.
HORIZON
DEPTH cm (in)
DESCRIPTION
All
0 - 23 (0 - 9)
Very dark greyish brown, 10 YR 3/2, moist; loamy
sand; structureless; loose consistence, dry;
smooth, clear boundary to:
A12
23 - 46 (9 - 18)
black, 10 YR 2/1, moist; gritty clay loam;
strong fine and medium granular structure; firm
consistence, moist, sticky, plastic consistence,
wet; smooth, clear boundary to:
CI
46 - 53 (18 - 21)
brown, 10 YR 3/3, moist; gritty sandy loam;
weak fine subangular blocky structure; friable
consistence, moist; smooth, diffuse boundary to:
C2
54 - 76 (21 - 30)
soil like the preceding horizon, but containing
much stony weathering material.
(80714)
30
PROFILE C
HORIZON
A12
DEPTH cm
31-43
7.24
Moisture 100-105°C %
2 0 0 M - 2 mm
%
13
50M - 200M
%
. 26
-
%
9
20M
2M <2M
50M
20M %
15
......
22
%
nd
CaCOg Equivalent %
17.3
Loss on Ignition % .
Organic Carbon %
4.2
Total Nitrogen %
0.43
10
C/N Ratio
pH in water (1:2.5)
6.0
pH in M/100 CaCl2
5.1
Exchangeable Calcium meq %
25.5
Exchangeable Magnesium meq %
10.3
Exchangeable Potassium meq %
0.45
Exchangeable Sodium meq %
0.01
Total Exchangeable Bases meq-%
36.3
Exchangeable Hydrogen meq %
13.3
Cation Exchange Capacity meq % (by addition)
49.6
73
Base Saturation %
nd = no determination or no sample;
(80714)
31
tr = trace;
• = nil
PROFILE D
CALCIMORPHIC SOIL, MOKHOTLONG SET
LOCATION:
By Blue Mountain Pass, Mountain Road about 2,670 m
(8,900 feet) elevation.
CLIMATE:
About 1,000 mm (40 in) annual rainfall.
SITE:
Straight slope (about 9°) southern aspect.
PARENT MATERIAL:
Developed from basaltic material.
VEGETATION:
Poor Themeda-Festuca
SOIL DRAINAGE:
Free, permeability moderately slow.
Alpine Veld.
HORIZON
DEPTH cm (in)
All
0 - 5 (0 - 2)
Thin colluvial topsoil • dark grey brown loamy
sand
A12
5 - 25 (2 - 10)
black, 10 YR 2/1, moist; stony loam; moderate
fine granular structure; firm consistence, moist;
slightly wavy, clear boundary to:
C
25 - 40 (10 .- 16)
very dark grey, 10 YR 3/1, moist; gritty sandy
loam; structureless; friable consistence, moist;
wavy, abrupt boundary to:
R
(80714)
at 40 (16)
DESCRIPTION
hard basalt lava.
32
PROFILE D
HORIZON
A12
DEPTH cm
8-21
Moisture 100-105°C %
8.37
2 0 0 M - 2 mm
50M - 2 0 0 M
%
21
•
%
29
20M
-
50M
%
16
2M
•
20M
%
13
<2M
%
4
'.
nd
CaCOg Equivalent %
17.4
Loss on Ignition %
Organic Carbon %
5.5
Total Nitrogen %
0.48
C/N Ratio
',.12
pH in water (1:2.5)
6.1
pH in M/100 CaCl2
5.2
11.8
Exchangeable Calcium meq %
Exchangeable Magnesium meq %
2.5
Exchangeable Potassium meq %
0.87
Exchangeable Sodium meq %
0.06
Total Exchangeable Bases meq %
15.2
Exchangeable Hydrogen meq %
17.7
Cation Exchange Capacity meq % (by addition)
32.9
46
Base Saturation %
nd • no determination or no sample;
(80714)
tr = trace;
• = nil
PROFILE E
VERTISOL OF LITHOMORPHIC ORIGIN, PHECHELA SET
LOCATION:
By Mapotu village, Mafeteng district.
CLIMATE:
About 500-630 mm (20-25 in) annual rainfall.
SITE:
Colluvial apron to a large sill (slope about 4°).
PARENT MATERIAL:
Developed from dolerite and doleritic drift material.
VEGETATION:
Cymbopoion - Themeda veld.
SOIL DRAINAGE:
Imperfect to poor, permeability slow.
HORIZON
DESCRIPTION
DEPTH cm (in)
All
0 - 20 (0 - 8)
A12
20 - 40 (8 - 16)
black, 2.5 Y 2/0, dry; clay; moderate medium
blocky structure; firm consistence, moist; very
hard consistence, dry; common carbonate
concretions and some hard doleritic stones;
smooth, gradual boundary to:
A13
40 - 61 (16 - 24)
very dark grey, ped exterior, 10 YR 3/1, dry or
very dark greyish brown, ped interior, 2.5 Y 3/2,
dry; gritty clay; moderate coarse blocky
structure; very hard consistence, dry; sparse
manganese shot and abundant carbonate concretions;
some doleritic stones; slightly wavy, clear
boundary to:
61 - 107 (24 - 42)
grey brown; mottled with variegated weathering
colours; sandy; weathering dolerite.
R
At 107 (42)
Note:
(80714)
Black, 10 YR 2/1, dry; clay; moderate medium
prismatic structure, breaking to blocks and
granules; firm consistence, moist, hard
consistence, dry, rare small carbonate concretions;
smooth, diffuse boundary to:
hard, only partially weathered dolerite.
Surface soil self-mulching.
Cracks not well developed
in this profile, but common elsewhere to base of
A horizon.
Some slickensides.
34
PROFILE E
HORIZON
All
A12
A13
DEPTH cm
0-13
23-36
51-61
5.64
5.40
5.15
Moisture 100-105°C %
2 0 0 M - 2 mm
%
6
16
17
50M - 200M
%
30
26
29
20M
-
50M
%
8
8
9
2M
-
20M
%
13
11
9
<2M
%
39
36
35
tr
CaCOg Equivalent %
5.6
4.8
6.2
4.5
Loss on Ignition %
7.7
Organic Carbon %
1.1
nd
nd
Total Nitrogen %
0.09
nd
nd
•«{12
nd
nd
C/N Ratio
pH in water (1:2.5)
8.5
8.9
9.1
pH in M/100 CaCl2
7.4
8.0
8.2
10.8
33.0
16.9
Exchangeable Calcium meq %
Exchangeable Magnesium meq %
29
27
27
Exchangeable Potassium meq %
0.73
0.34
0.21
Exchangeable Sodium meq %
1.97
1.95
2.66
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
46.8
1.7
0.6
0.1
44.2
62.9
46.9
=
99
0.6
Soluble Salts meq %
(by conductivity)
(80714)
62.3
96
Base Saturation %
nd
42.5
no determination or no sample;
35
1.2
tr = trace;
- - nil
100
1.3
PROFILE F
VERTISOL OF LITHOMORPHIC ORIGIN, SEMONKONG SET
LOCATION:
By stream bank in Upper Makhaleng Valley, Maseru district.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Almost flat valley floor.
PARENT MATERIAL:
Developed from basaltic colluvium.
VEGETATION:
Poor Themeda veld.
SOIL DRAINAGE:
Imperfect, permeability moderately slow.
DESCRIPTION
HORIZON DEPTH cm (in)
All
0 - 23 ( 0 - 9 )
A12
23 -86 (9 - 34)
very dark brown, 10 YR 2/2, dry; clay loam;
moderate to strong medium prismatic structure;
firm consistence, moist, sticky, plastic
consistence, wet; much iron staining along
structure separations; slightly wavy, gradual
boundary to:
CI
86 - 109 (34 - 43)
dark brown; faintly grey mottled; massive, gritty
clay colluvium.
C2
109 - 123 (43 - 48)
Stone-line horizon of sub-angular basaltic
pebbles and stones of varying size in dark brown
clay matrix.
C3
123 - 152 (48 - 60)
Horizon similar to CI but grey mottles replaced
by coarse yellowish-brown patches.
i.
.1
l
(80714)
plus
Dark brown, 10 YR 4/3, dry, or very dark greyish
brown 10 YR 3/2, moist; fine sandy clay loam;
structureless; friable consistence, moist;
smooth clear boundary to:
36
PROFILE F
HORIZON
All
A12
DEPTH cm
3-15
25-41
CI
A12
64-76 .
97-109
4.52
5.65
5.46
6.45
%
7
12
8
3
50/i - 200/A %
35
31
30
28
Moisture 100-105°C %
2 0 0 M - 2 mm
20M
-
50M
%
10
12
12
8
2M
-
20M
%
18
18
19
23
<2M
%
21
13
18
30
nd
nd
nd
nd
CaCOg Equivalent %
Loss on Ignition %
11.3
15.2
15.0
11.0
Organic Carbon %
3.0
nd
nd
nd
Total Nitrogen %
0.26
nd
nd
nd
12
nd
nd
nd
C/N Ratio
pH in water (1:2.5)
6.0
6.3
6.6
6.8
pH in M/100 CaCl2
5.0
5.5
5.8
5.9
16.5
32.0
33.8
22.4
Exchangeable Calcium meq %
9.3
14
12
0.60
0.20
0.20
0.20
0.13
0.18
0.18
0.21
Exchangeable Magnesium meq %
8.6
Exchangeable Potassium meq %
Exchangeable Sodium meq %
Total Exchangeable Bases meq %
25.8
46.4
46.2
32.1
Exchangeable Hydrogen meq %
11.0
13.0
10.5
7.6
Cation Exchange Capacity meq %
(by addition)
36.8
59.4
56.7
39.7
70
Base Saturation %
nd = no determination or no sample;
(80714)
37
81
78
tr = trace;
• - nil
81
PROFILE G
VE1TISOL OF LITHOMORPHIC OHIGIN, SEMONKONG SET
LOCATION:
By Kubutu Store, Maseru district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Broad, straight slope on about 2° of a pediplain.
A slightly accumulating position.
PARENT MATERIAL:
Developed from colluvial drift of basaltic origin.
LAND USE:
On edge of maize field.
SOIL DRAINAGE:
Imperfect, permeability slow.
HORIZON
Ap/A12
DEPTH cm (in)
0 - 48 (0 - 19)
DESCRIPTION
Black, 10 YR 2/1, moist; clay; moderate
medium blocky structure; firm consistence,
moist; plastic consistence, wet; surface selfmulching; cracks to horizon base; slickensides
common; smooth, gradual boundary to:
CI
48 - 76 (19 - 30)
very dark grey, 2.5 Y 3/1, moist; clay;
coarsly mottled with grey brown and manganese
stained; massive; firm consistence, moist;
sticky, plastic consistence, wet; smooth,
gradual boundary to:
C2
76 - 130 (30 - 51)
plus
dark greyish brown, 2.5 Y 4/2, moist; clay;
massive; firm consistence, moist; sticky,
plastic consistence, wet; some small
manganese shot.
(80714)
38
PROFILE G
HORIZON
Ap
A12
CI
DEPTH cm
0-13
18-31
51-64
5.93
7.83
7.89
%
2
2
1
Moisture 100-105°C %
2 0 0 M - 2 mm
50M
- 200M
%
29
29
20
20M
-
50M
%
10
7
4
2M
-
20M
%
19
17'
11
2M
%
32
37
61
-
-
-
<
CaCOg Equivalent %
10.9
Loss on Ignition %
8.7
11.9
Organic Carbon %
3.1
nd
Total Nitrogen %
0.22
nd
nd
14
nd
nd
C/N Ratio
-
nd
pH in water (1:2.5)
6.5
6.9
7.5
pH in M/100 CaCl2
5.3
5.9
6.6
Exchangeable Calcium meq %
26.9
33.3
32.1
Exchangeable Magnesium meq %
10.5
13
1.5
Exchangeable Potassium meq %
0.51
0.40
0.55
Exchangeable Sodium meq %
0.14
0.20
0.33
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
38.1
46.9
48.0
8.4
6.4
3.4
46.5
53.3
51.4
. nd = no determination or no sample;
(80714)
88
82
Base Saturation %
39
tr - trace;
- - ni1
93
PROFILE H
VERTISOL OF TOPOGRAPHIC DEPRESSIONS, THULO SET
LOCATION:
By stream at Palama, near fork to Morija.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Developed from a deep pedisediment on the straight, broad
lower erosion slope (about 2°) of a dissected peneplain.
PARENT MATERIAL:
Pedisediments.
LAND USE:
Maize field.
SOIL DRAINAGE:
Imperfect to poor, permeability slow.
HORIZON
DESCRIPTION
DEPTH cm (in)
Ap
0 - 18 (0 - 7)
Black 10 YR 2/1, moist; clay; weak medium
prismatic structure, breaking to fine blocky;
very firm consistence, moist, sticky, plastic
consistence, wet; surface crusty; smooth,
diffuse boundary to:
A12
18 - 46 (7 - 18)
very dark grey, 10 YR 3/1, moist; clay;
moderate medium blocky structure; very firm
consistence, moist; very sticky, very plastic
consistence, wet; cracks to base of horizon;
rare, small, black manganese shot; smooth,
diffuse boundary to:
Clca
46 - 73 (18 - 29)
very dark grey, 5 Y/l, moist; clay; distinctly
mottled with yellowish brown; moderate medium
blocky structure; firm consistence, moist;
sticky, plastic consistency, wet; some manganese
shot and fine carbonate segregations and rare
carbonate concretions; slightly wavy, gradual
boundary to:
C2ca
73 - 99 (29 - 39)
intimate intermottle of grey, 5 Y 5/1, moist
and yellowish brown, 10 YR 5/6, moist, with also
some streaks and pockets of very dark grey, 5Y
hue; sandy clay; almost massive; firm
consistence, moist; plastic, consistence, wet;
frequent small, hard carbonate concretions;
slightly wavy, gradual boundary to:
C3ca
99
(80714)
147 (39
plus
58)
yellowish brown, hard and dry pedisediment.
40
PROFILE H
HORIZON
Clca
Ap
A12
DEPTH cm
0-13
23-36
51-64
Moisture 100-105°C %
3.48
5.98
3.96
%
3
5
6
50M - 200M
%
23
15
28
20M
-
50M
%
4
4
3
2M
-
20M
%
22
22
18
<2M
%
44
51
44
nd
-
21.3
8.2
5.6
2 0 0 M - 2 mm
CaCOg Equivalent %
Loss on Ignition %
8.0
Organic Carbon %
1.8
nd
nd
Total Nitrogen %
0.23
nd
nd
12
nd
nd
C/N Ratio
pH in water (1:2.5)
6.2
7.2
8.5
pH in M/100 CaCl2
5.5
6.1
7.7
17.1
22.1
47.4
Exchangeable Calcium meq %
12
13
0.85
0.91
0.73
0.25
0.46
0.59
Exchangeable Magnesium meq %
7.6
Exchangeable Potassium meq %
Exchangeable Sodium meq %
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
25.8
35.5
5.6
3.5
31.4
39.0
82
Base Saturation %
nd = no determination or no sample;
(80714)
41
tr = trace;
91
• - nil
61.7
nd
61.7
100
PROFILE I
VERTISOL OF TOPOGRAPHIC DEPRESSIONS, KHABOS SET
LOCATION:
800 m (Vi mile) upstream from ford, Thaba Phatsoa area,
Leribe district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Almost flat stream terrace.
PARENT MATERIAL:
Developed from riverine alluvium.
VEGETATION:
Poor grass, on edge of cultivated land.
SOIL DRAINAGE:
Imperfect, permeability slow.
HORIZON
DESCRIPTION
DEPTH cm (in)
Very dark greyish brown, 10 YR 3/2, moist; fine
sandy clay loam; weak fine and medium blocky
structure; friable consistence, moist; slightly
sticky, slightly plastic consistence, wet;
surface crusty; slightly wavy, clear boundary
to:
All
0 - 23 (0 - 9)
A12
23 - 70 (9 - 28)
very dark grey, 10 YR 3/1, moist; clay loam;
weak coarse blocky, breaking to medium blocky
structure; firm consistence, moist; sticky,
plastic consistency, wet; cracks to 18 in;
smooth, diffuse boundary to:
CI
70 - 131 (28 - 52)
plus
complex mixture of very dark greyish brown,
10 YR 3/2, moist, with some very dark grey,
10 YR 3/1, moist; clay; massive; firm
consistence, moist; sticky, plastic consistence,
wet.
(80714)
42
PROFILE I
All
A12
A12
CI
DEPTH cm
3-15
25-38
51-64
79-97
Moisture 100-105°C %
2.81
5.80
5.56
3.77
HORIZON
2 0 0 M - 2 mm
%
5
2
3
4
50M - 2 0 0 M
%
49
40
37
42
20M
-
50M
%
9
12
15
16
2M
-
20M
%
12
18
16
11
<2M
%
20
21
23
24
nd
nd
nd
nd
CaCOj Equivalent %
8.3
9.2
5.7
Loss on Ignition %
7.1
Organic Carbon %
2.0
nd
nd
nd
Total Nitrogen %
0.19
nd
nd
nd
nd
nd
nd
11.
C/N Ratio
pH in water (1:2.5)
5.4
5.2
5.7
6.4
pH in M/100 CaCl2
4.7
4.4
4.8
5.4
10.1
13.5
19.3
15.8
Exchangeable Magnesium meq %
3.9
5.5
7.4
7.3
Exchangeable Potassium meq %
1.47
0.64
0.34
0.33
Exchangeable Sodium meq %
0.06
0.13
0.17
0.19
Exchangeable Calcium meq %
Total Exchangeable Bases meq %
15.5
19.8
27.2
23.6
7.9
14.5
9.9
4.5
23.4
34.3
37.1
28.1
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
nd = no determination or no sample;
(80714)
58
66
Base Saturation %
43
tr = trace;
- - nil
73
84
PROFILE J
CLAYPAN SOIL, MASERU SET
LOCATION:
By deep erosion gulley, Agricultural Experimental Station,
Maseru.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Lower erosion slope of about 3° of a dissected peneplain.
PARENT MATERIAL:
Developed from deep pedisediment over Red Beds sandstone.
VEGETATION:
Poor grass.
SOIL DRAINAGE:
Imperfect, permeability slow.
HORIZON
DEPTH cm (in)
DESCRIPTION
Al
0 - 23 (0 - 9)
Brown, 10 YR 5/3, dry, (brown, 10 YR 4/3,
moist) fine sandy loam; almost structureless;
loose consistence, dry; smooth, diffuse
boundary to:
A2
23 - 35 (9 - 14)
light grey, 10 YR 7/2, almost dry; fine sandy
loam, with fine, faint, yellowish brown
mottles; structureless; loose consistence,
dry; rare small shot-like Fe concretions;
slightly wavy, abrupt boundary to:
IIB21t
35 - 48 (14 - 19)
greyish brown, 2.5 Y 5/2, dry; clay loam,
with smooth and continuous very dark greyish
brown, clay skins on ped exterior; strong
coarse prismatic structure; hard consistence,
dry, firm consistence, moist; common Fe
concretions; smooth, gradual boundary to:
IIB22t
48 - 76 (19 - 30)
greyish brown, 2.5 Y 5/2; dry; clay loam;
clay skins less well developed than in
preceding horizon; strong medium blocky
structure; very hard consistence, dry; very
firm consistence, moist; abundant rounded Fe
concretions of all sizes; slightly wavy,
clear boundary to:
HCl
76 - 131 (30 - 52)
light grey; mottled with yellowish brown;
hard dry pedisediment; abundant iron and lime
concretions.
73)
Yellow pedisediment; mottled in shades of
brown; abundant Fe concretions and some
calcium concretions; black manganese stains
along cracks. At 215 cm in donga, a grit bed,
mostly pea-shaped iron concretions with
larger, more angular pieces of sandstone,
agate and more rarely, weathering dolerite.
IIC2
(80714)
131 - 186 (52
plus
44
PROFILE J
HORIZON
Al
A2
DEPTH cm
0-13
Moisture 100-105°C %
HCl
IIB21t
IIB22t
25-34
41-48
58-71
97-109
0.99
1.26
2.11
3.51
2.66
2 0 0 M - 2 mm
%
7
5
4
4
3
50M - 200M
%
51
43
40
35
47-
20M
-
%
20
24
18
16
12
2M
-
12
16
15
17
16
<2M
%
9
11
23
28
22
nd
nd
-
tr
-
50M
20M
%
CaCOg Equivalent %
2.0
2.0
2.5
Organic Carbon %
0.6
0.2
0.3
nd
nd
Total Nitrogen %
0.06
0.03
0.04
nd
nd
10
7
8
nd
nd
C/N Ratio
2.9
2.3
Loss on Ignition %
pH in water (1:2.5)
5.9
6.0
8.1
9.0
8.5
pH in M/100 CaCl 2
5.2
5.3
6.7
7.4
6.9
Exchangeable Calcium meq %
1.5
1.5
4.6
6.7
4.6
Exchangeable Magnesium meq %
0.75
0.64
4.2
5'. 7
3.7
Exchangeable Potassium meq %
0.18
0.05
0.25
0.40
0.26
Exchangeable Sodium meq %
0.09
0.16
1.69
2.94
1.97
Total Exchangeable Bases meq %
2.5
2.4
10.7
15.7
10.5
Exchangeable Hydrogen meq %
2.3
1.0
1.2
0.7
0.9
Cation Exchange Capacity meq %
(by addition)
4.8
3.4
11.9
16.4
11.4
Base Saturation %
52
71
90
96
92
Soluble Salts meq/lOOg
(by conductivity)
0.2
0.1
0.3
0.4
0.3
Exchangeable Sodium %
1.9
4.7
14.2
17.8
17.3
nd = no determination or no sample;
(80714)
45
tr - trace;
- - nil
PROFILE K
CLAYPAN SOIL, MASERU SET
LOCATION:
Near Mokhele village, Mafeteng district.
CLIMATE:
About 500-630 mm (20-25 in) annual rainfall.
SITE:
Broad, straight lower erosion slope of about 4° of a
dissected peneplain.
PARENT MATERIAL:
Developed from pedisediment overlying Beaufort sandy
shales.
LAND USE:
On verge of maize field.
SOIL DRAINAGE:
Imperfect, permeability slow.
HORIZON
DEPTH cm (in)
DESCRIPTION
AP
0 - 38 (0 - 15)
Brown, 10 YR 5/3, dry, (dark brown, 10 YR 4/3,
moist) fine sandy loam; structureless; loose
consistence, dry; some FeMn concretions at
horizon base; smooth, clear boundary to:
IIB21t
38 - 50 (15 - 20)
greyish brown, 2.5 Y 5/2, moist; clay; weak
medium blocky structure; firm consistence,
moist; smooth, diffuse boundary to:
IIB22t
50 - 68 (20 - 27)
dark greyish brown, 2.5 Y 4/2, moist; clay;
moderate medium blocky structure; very firm
consistence, moist; smooth, clear boundary to:
68 - 112 (27 - 44)
yellowish brown, 10 YR 5/4, slightly moist;
clay; slightly mottled with olive brown;
coarse blocky structure, almost massive; very
firm consistence dry.
IIC
(80714)
46
PROFILE K
AP
HORIZON
Ap
IIB21t
He
DEPTH cm
0-13
25-38
39-50
68-81
Moisture 100-105T %
1.61
2.06
5.46
5.14
2 0 0 M - 2 mm
%
8
7
4
3
50M - 200M
%
38
42
35
23
20M
-
50M
%
16
10
3
8
2M
-
20M
%
15
20
12
22
<2M
%
21
20
44
44
nd
nd
-
1.3
4.6
CaCC^ Equivalent %
Loss on Ignition %
4.0
3.5
6.4
Organic Carbon %
1.0
1.1
0.9
nd
Total Nitrogen %
0.13
0.13
0.13
nd
8
9
7
nd
C/N Ratio
6.7
9.0
5.4
7.9
2.6
7.2
27.9
2.2
2.2
8.8
Exchangeable Potassium meq %
0.43
0.23
0.47
0.67
Exchangeable Sodium meq %
0.35
1.16
3.10
4.71
Total Exchangeable Bases meq %
5.2
6.2
19.6
46.3
Exchangeable Hydrogen meq %
6.0
5.9
4.9
0.3
11.2
12.1
24.5
46.6
pH in water (1:2.5)
5.2
5.2
pH in M/100 CaCl2
4.3
4.4
Exchangeable Calcium meq %
2.2
Exchangeable Magnesium meq %
Cation Exchange Capacity meq %
(by addition)
46
Base Saturation %
0.3
Soluble Salts meq/100g
(by conductivity)
nd = no determination or no sample;
(80714)
47
-
80
51
1.0
tr - trace;
1.1
- = nil
13
99
1.5
PROFILE L
CLAYPAN SOIL,SEPHULA SET
LOCATION:
800 m (% mile) from Sephula village, Mafeteng district, by
track to main road.
CLIMATE:
About 630 mm (25 in) annual rainfall.
SITE:
A broad, flattish-topped slope crest, sloping about 1°.
PARENT MATERIAL:
Developed from colluvial drift over Molteno sandstone.
LAND USE:
Field fallow, after wheat.
SOIL DRAINAGE:
Imperfect, permeability slow.
HORIZON
AP
DEPTH cm (in)
0 - 31 (0 - 12)
DESCRIPTION
Brown, 10 YR 5/3, dry (dark brown, 10 YR 4/3,
moist)loamy fine sand; structureless; loose
consistence, moist; some rounded FeMn
concretions; smooth, gradual boundary to:
A12
31 - 40 (12 - 16)
soil similar to horizon Ap, but containing
abundant hard and rounded small FeMn concretions;
smooth, clear boundary to:
IIB21t
40 - 70 (16 - 28)
strong brown, 7.5 YR 5/6, moist; clay, with
olive brown mottles; weak, fine and medium
blocky structure; firm consistence, moist; rare
FeMn concretions; smooth, clear boundary to;
IIB22t
70 - 102 (28 - 40)
greyish brown, 2.5 Y 5/2, moist; clay;
coarsly mottled with yellowish brown and
manganese stained; moderate medium blocky
structure; very firm consistence, moist;
smooth gradual boundary to:
IIC
(80714)
102 - 134 (40 - 53) massive light olive brown clay,
plus
48
PROFILE L
HORIZON
AP
Ap
IIB21t
IIB22t
DEPTH cm
0-13
18-31
46-56
74-86
Moisture 100-105°C %
0.69
1.23
9.49
6.89
20
11
6
3
%
63
57
26
16
20/Li - 50/x %
5
10
3
4
3
8
4
18
8
13
60
56
nd
nd
nd
-
200^ - 2 mm %
50/u
- 200M
2M
-
<2M
%
20M
%
CaCOo Equivalent %
8.9
Loss on Ignition %
1.4
2.3
7.4
Organic Carbon %
0.3
0.4
0.5
nd
Total Nitrogen %
0.03
0.05
0.10
nd
C/N Ratio
10
8
5
nd
pH in water (1:2.5)
6.0
6.0
6.3
7.5
pH in M/100 CaCl2
4.9
4.8
5.1
6.2
Exchangeable Calcium meq %
0.7
1.5
7.5
11.0
Exchangeable Magnesium meq %
0.19
0.56
5.2
7.7
Exchangeable Potassium meq %
0.21
0.22
2.12
3.29
Exchangeable Sodium meq %
0.07
0.09
0.23
0.98
Total Exchangeable Bases meq %
1.2
2.4
15.1
23.0
Exchangeable Hydrogen meq %
1.7
2.8
4.9
3.3
Cation Exchange Capacity meq %
(by addition)
2.9
5.2
20.0
26.3
Base Saturation %
Soluble Salts meq/100g
(by conductivity)
41
0.1
76
46
0.1
0.2
87
0.3
-
nd = no determination or no sample;
(80714)
49
tr = trace;
- = nil
PROFILE M
BROWN SOIL OF SEMI-ARID REGIONS, MATS'ABA
SET
LOCATION:
Near fork in the road to Ramapepe, Leribe district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
On the level top of a small dolerite sill.
PARENT MATERIAL:
Developed from weathering dolerite and some colluvial drift
of similar origin.
VEGETATION:
"SOIL DRAINAGE:
HORIZON
Al
Themeda veld.
Free, permeability moderately rapid.
DEPTH cm (in)
0 - 25 (0 - 10)
DESCRIPTION
Reddish brown, 5 YR 4/4, moist; fine sandy
loam; structureless; friable consistence,
moist; smooth, gradual boundary to:
Bl
25 - 43 (10 - 17)
yellowish red, 5 YR 4/6, moist; fine sandy
clay loam; weak fine blocky structure;
friable consistence, moist; rare small angular
dolerite stones; smooth, gradual boundary to:
B2
43 - 58 (17 - 23)
yellowish red, 5 YR 4/8, moist; fine sandy clay
loam; weak fine blocky structure; friable
consistence, moist; sticky, slightly plastic
consistence, wet; very rare rounded Fe
concretions and some small dolerite stones;
slightly wavy, gradual boundary to:
C
5 8 - 8 1 (23 - 32)
brownish yellow, 10 YR 6/6, moist; gritty,
fine sandy loam; structureless; friable
consistence, moist; frequent angular fragments
of dolerite of varying sizes and some soft
black manganese concretions and stains; wavy,
abrupt boundary to
R
at 81 (32)
hard, but partially weathered, doleritic rock.
(80714)
50
PROFILE M
Al
HORIZON
Bl
Q
C
DEPTH cm
3-15 '
28-41 I
61-76 \
Moisture 100-105°C %
1.05
1.78
2.87
%
7
4
14
2 0 0 M - 2 mm
50M
- 200M
%
59
51
48
20M
-
50M
%
12
9
8
2M
-
20M
%
7
11
11
2M
%
13
23
16
nd
nd
nd
<
CaC03 Equivalent %
3.0
Organic Carbon %
0.7
nd
nd
Total Nitrogen %
0.08
nd
nd
nd
nd
C/N Ratio
4.0
5.0
Loss on Ignition %
9
pH in water (1:2.5)
4.6
5.2
5.3
pH in M/100 CaCl2
4.0
4.1
4.1
Exchangeable Calcium meq %
1.3
1.5
2.4
Exchangeable Magnesium meq %
0.70
1.1
2.2
Exchangeable Potassium meq %
0.43
0.17
0.19
Exchangeable Sodium meq %
0.08
0.13
0.22
Total Exchangeable Bases meq %
2.5
2.9
5.0
Exchangeable Hydrogen meq %
4.3
5.6
6.1
Cation Exchange Capacity meq %
(by addition)
6.8
8.5
11.1
nd = no determination or no sample;
(80714)
34
37
Base Saturation %
51
tr = trace;
- = nil
45
PROFILE N
EUTROPHIC BROWN S O I L ,
MACHACHE SET
LOCATION:
By road, 400m (l4 mile) west of Ntsi village, Maseru
district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Broad pediment slope of about 4°*
PARENT MATERIAL:
Developed from colluvial drift of basaltic origin.
LAND USE:
Poor grass, cultivated land.
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
AP
DEPTH cm (in)
0 - 13 (0 - 5)
DESCRIPTION
Reddish brown, 5 YR 4/3, moist; clay loam;
weak fine granular structure; friable
consistence, moist; smooth, gradual boundary to:
Bll
13 - 38 (5 - 15)
reddish brown, 5 YR 4/4, moist; clay; almost
structureless; friable consistence, moist;
smooth, gradual boundary to:
B12
38 - 63 (15 - 25)
yellowish red, 5 YR 4/6, moist; clay; weak
fine sub-angular blocky structure; friable
consistence, moist; smooth, diffuse boundary
to:
IIB2
63 - 127 (25 - 50)
red, 2.5 YR 4/8; clay; weak fine sub-angular
blocky structure; friable consistence, moist.
A thin stone line of angular fragments of
weathering basalt occurs in the upper part of
this horizon.
(80714)
52
PROFILE N
HORIZOIV
AP
Bll
B12
IIB2
DEPTH cm
3-13
21-33
46-58
76-89
2.32
4.11
5.38
7.33
%
2
4
2
8
%
35
31
32
22
Moisture 100-105°C %
2 0 0 M - 2 mm
50M
- 200M
20M
-
50M
%
12
8
16
11
2M
-
20M
%
14
12
14
15
31
42
30
37
nd
nd
nd
nd
< 2M %
CaCOg Equivalent %
7.3
9.1
Loss on Ignition %
8.9
Organic Carbon %
2.0
nd
nd
nd
Total Nitrogen %
0.19
nd
nd
nd
11
nd
nd
nd
C/N Ratio
10.7
pH in water (1:2.5)
5.4
5.6
5.3
5.6
pH in M/100 CaCl2
4.3
4.5
4.3
4.6
Exchangeable Calcium meq %
2.9
1.6
2.9
5.4
Exchangeable Magnesium meq %
1.6
2.1
2.2
7.4
Exchangeable Potassium meq %
0.86
0.17
0.25
0.24
Exchangeable Sodium meq %
0.11
0.18
0.17
0.24
Total Exchangeable Bases meq %
5.5
4.1
5.5
13.3
Exchangeable Hydrogen meq %
10.3
6.8
8.8
8.0
Cation Exchange Capacity meq %
(by addition)
15.8
10.9
14.3
21.3
35
Base Saturation %
nd = no determination or no sample;
(80714)
53
38
38
tr = trace;
- = nil
62
PROFILE O
FERSIALLITIC SOIL, LERIBE SET
LOCATION:
By camp, Tsiu's Dam, Maseru district.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Stable, slightly convex, broad slope of about 3° below a
slope crest.
PARENT MATERIAL:
Developed from colluvial drift over Red Beds sandstone.
VEGETATION:
Overgrazed Cymbopoion-Themeda
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
DEPTH cm (in)
veld.
DESCRIPTION
All
0 - 13 (0 - 5)
A12
13 - 35 (5 - 14)
reddish brown, 5 YR 4/4, moist; fine sandy
loam; structureless; friable consistence,
moist; smooth, gradual boundary to:
IIB21
35 - 70 (14 - 28)
red, 2.5 YR 4/6, moist; fine sandy clay loam;
structureless; friable consistence, moist;
slightly sticky, slightly plastic consistence,
wet; some small shot-like FeMn concretions;
smooth, diffuse boundary to:
IIB22
70 - 127 (28 - 50)
red, 2.5 YR 4/8, moist; fine sandy clay; very
weak fine to medium blocky structure; friable
consistence, moist; smooth, gradual boundary
to:
127 - 165 (50 - 65)
plus
dark reddish brown, 5 YR hue; clay; firm,
compact consistence, moist; much manganese
stained and containing frequent rounded FeMn
concretions.
IIC
(80714)
Reddish brown, 5 YR 4/4, dry (brown, 7.5 YR
4/4, moist) fine sandy loam; very weak fine
blocky structure-almost structureless; friable
consistence, moist; smooth, gradual boundary
to:
54
PROFILE O
HORIZON
All
A12
IIB21
IIB22
DEPTE cm
0-13
14-25
36-46
71-81
Moisture 100-105°C %
0.92
1.55
2.72
4.04
200M
- 2 mm
%
8
7
7
5
50M
- 200M
%
54
51
46
39
20M
-
50M
%
14
16
12
8
2M
-
20M
%
8
8
4
4
2M
%
15
17
30
42
nd
nd
nd
nd
CaCOg Equivalent %
2.7
4.3
5.9
Loss on Ignition %
2.3
Organic Carbon %
0.4
nd
nd
nd
Total Nitrogen %
0.05
nd
nd
nd
nd
nd
nd
C/N Ratio
8
pH in water (1:2.5)
5.3
5.7
5.3
6.0
pH in M/100 CaCl2
4.5
4.8
4.7
5.2
Exchangeable Calcium meq %
1.3
1.7
2.3
2.8
Exchangeable Magnesium meq %
0.63
0.78
1.5
2.8
Exchangeable Potassium meq %
0.42
0.33
0.21
0.27
Exchangeable Sodium meq %
0.10
0.09
0.09
0.15
Total Exchangeable Bases meq %
2.5
2.9
4.1
6.0
Exchangeable Hydrogen meq %
2.6
2.7
3.3
. 3.6
Cation Exchange Capacity meq %
(by addition)
5.1
5.6
7.4
9.6
Base Saturation %
49
nd ° no determination or no sample;
(80714)
55
55
52
tr = trace;
- = nil
63
FERSIALLITIC SOIL,
PROFILE P
LERIBE SET
LOCATION:
By main road 800 m (lA m i l e ) west of S t . Monica Mission,
Leribe d i s t r i c t .
CLIMATE:
About 760-875 mm (30-35 i n ) annual
SITE:
C r e s t of a h i l l of Red Beds sandstone with a slope of about 2°.
PARENT MATERIAL:
Developed from colluvial drift.
LAND USE:
Old cropland, now rough grass.
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
Ap
DEPTH cm (in)
rainfall.
DESCRIPTION
0 - 13 (0 - 5)
Reddish brown, 5 YR 4/3, moist; fine sandy
loam; structureless; friable consistence,
moist; smooth, gradual boundary to:
A12
13 - 25 (5 - 10)
reddish brown, 5 YR 4/4, moist; fine sandy
loam; friable consistence, moist; smooth,
gradual boundary to:
Bl
25 - 40 (10 - 16)
yellowish red, 5 YR 4/6, moist; fine sandy
clay loam; structureless; friable consistence,
moist; smooth, gradual boundary to:
IIB21
40 - 73 (16 - 29)
red, 2.5 YR 4/6, moist; fine sandy clay loam;
very weak fine sub-angular blocky structure;
friable consistence, moist; slightly sticky,
very slightly plastic consistence, wet; smooth,
diffuse boundary to:
IIB22
73
red, 2.5 YR 4/8, moist; fine sandy clay loam;
very weak fine sub-angular blocky structure;
firm to friable consistence, moist; slightly
sticky, slightly plastic consistence, wet.
(80714)
137 (29 - 54).
plus
56
PROFILE P
HORIZON
Ap
A12
IIB21
IIB21
DEPTH cm
3-13
15-25
43-54
61-74
Moisture 100-105°C %
1.02
1.51
2.21
3.95
4
3
4
3
%
54
47
51
42
20/i -
50/x %
17
19
12
14
2/x -
20ft %
9
13
9
7
14
16
24
33
nd
nd
nd
nd
200^ - 2 mm %
50(j.
<2M
-
200fj.
%
CaCOg Equivalent %
Loss on Ignition %
3.0
Organic Carbon %
0.5
nd
nd
nd
Total Nitrogen %
0.06
nd
nd
nd
nd
nd
nd
3.9
8
C/N Ratio
3.8
4.3
pH in water (1:2.5)
5.1
5.8
5.6
5.9
pH in M/100 CaCl2
4.3
4.8
4.8
5.1
Exchangeable Calcium meq %
1.3
2.5
1.8
1.6
Exchangeable Magnesium meq %
0.59
1.0
1.1
2.0
Exchangeable Potassium meq %
0.37
0.23
0.18
0.21
Exchangeable Sodium meq %
0.10
1.10
1.12
0.11
Total Exchangeable Bases meq %
2.4
3.8
3.2
3.9
Exchangeable Hydrogen meq %
3.6
3.2
3.4
3.2
Cation Exchange Capacity meq %
(by addition)
6.0
7.0
6.6
7.1
40
Base Saturation %
nd
(80714)
=
no determination or no sample;
57
tr - trace;
54
- - nil
48
55
PROFILE 0
FERSIALLITIC SOIL, BEREA SET
LOCATION:
About 400 m (l4 mile) from Maqalika Village, Maseru
district.
CLIMATE:
About 760 mm (30 in) annual rainfall.
SITE:
Stable, straight slope of about 4° immediately below a
slope crest.
PARENT MATERIAL:
Derived from drift material overlying dull yellow coloured
Red Beds sandstone.
VEGETATION:
Overgrazed Cymbopogon-Themeda
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
DEPTH cm (in)
veld.
DESCRIPTION
All
0 - 15 (0 - 6)
Light yellowish brown, 10 YR 6/4, very slightly
moist; loamy fine sand; very weak fine and
medium granular structure; very friable
consistence, moist; smooth, diffuse boundary to:
A12
15 - 40 (6 - 16)
yellowish brown, 10 YR5/4, moist; loamy fine
sand; structureless; friable consistence,
moist; common rounded|FeMn concretions; smooth,
gradual boundary to:
Bl
40 - 58 (16 - 23)
yellowish brown, 10 YR 5/6, moist; fine sandy
loam, finely and faintly mottled with strong
brown; structureless; friable consistence,
moist; very common rounded FeMn concretions;
smooth, gradual boundary to:
B2
58 - 76 (23 - 30)
yellowish brown, 10 YR 5/8, moist; fine sandy
loam; distinct, common, coarse red-brown
mottles; very weak fine blocky structure;
friable consistence, moist; common FeMn concretions; smooth gradual boundary to:
CI
C2
(80714)
76 - 102 (30 - 40)
102 (40)
plus
yellowish brown, 10 YR 5/4, moist; fine sandy
clay with variegated weathering colours; weak
medium blocky structure; firm consistence,
moist; slightly sticky, slightly plastic
consistence, wet; sparse FeMn concretions;
slightly wavy, clear boundary to:
yellow; gritty sand with much black manganese
staining.
58
PROFILE 0
HORIZON
All
A12
DEPTH cm
3-13
23-36
43-56
66-76
86-100
Moisture 100-105°C %
0.81
0.49
0.82
1.35
2.11
200/i - 2 mm %
14
18
19
14
20
50/z - 200/Lt %
47
61
54
55
41
20^ -
50/A %
17
8
8
8
6
- 20/x %
10
4
5
3
6
11
9
13
19
26
nd
nd
nd
nd
nd
2M
<2^%
CaCOg Equivalent %
Bl
CI
B2
1.9
2.7
4.0
Loss on Ignition %
2.2
1.4
Organic Carbon %
0.5
0.2
nd
nd
nd
Total Nitrogen %
0.05
0.03
nd
nd
nd
•7
nd
nd
nd
10
C/N Ratio
pH in water (1:2.5)
5.8
5.7
5.8
5.5
5.3
pH in M/100 CaCl2
4.7
4.7
4.8
4.5
4.3
Exchangeable Calcium meq %
1.7
1.2
1.3
1.3
2.0
Exchangeable Magnesium raeq %
0.57
0.59
0.82
1.3
1.8
Exchangeable Potassium raeq %
0.28
0.12
0.13
0.12
0.17
Exchangeable Sodium meq %
0.09
0.10
0.12
0.09
0.12
Total Exchangeable Bases meq %
2.6
2.0
2.4
2.8
4.1
Exchangeable Hydrogen meq %
2.9
1.5
1.7
2.6
4.2
Cation Exchange Capacity meq %
(by addition)
5.5
3.5
4.1
5.4
8.3
Base Saturation %
47
nd = no determination or no sample;
(80714)
59
57
tr = trace;
59
- = nil
52
49
PROFILE R
FERRALLITIC SOIL,
LOCATION:
THEBE SET
On Berea P l a t e a u , by end of m o t o r a b l e t r a c k from L a n c e r s '
Gap.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Near the foot of a straight slope of about 2° on a
pediplain.
A slightly accumulating site.
PARENT MATERIAL:
Developed from colluvial drift over Cave Sandstone.
VEGETATION:
Overgrazed Cymbopoion-Themeda
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
All
DEPTH cm (in)
0 - 23 (0 - 9)
veld.
DESCRIPTION
Dark brown, 10 YR 4/3, dry, (dark brown,
10 YR 3/3, moist) fine sandy loam; almost
structureless; loose consistence, moist;
smooth, gradual boundary to:
brown, 10 YR 5/3, dry (dark brown, 10 YR 4/3,
moist) fine sandy loam; structureless; loose
to friable consistence, moist; smooth,
gradual boundary to:
A12
23 - 38 (9 - 15)
Bl
38 - 50 (15 - 20)
yellowish brown, 10 YR 5/6, moist; fine
sandy loam; structureless; friable consistence, moist; smooth, diffuse boundary to:
B21
50 - 88 (20 - 35)
brownish yellow, 10 YR 6/6, moist; fine
sandy clay loam; structureless; friable
consistence, moist; sparse, hard and rounded
iron concretions; smooth, diffuse boundary
to:
B22
88 - 131 (35 - 52)
pl u s
brownish yellow, 10 YR 6/6, moist; fine
sandy clay; very weak, fine and medium
blocky structure; firm to friable consistence,
moist; slightly plastic, slightly sticky consistence, wet; some hard iron concretions
increasing in amount with depth.
(80714)
60
PROFILE R
Bl
HORIZON
All
A12
DEPTH cm
0-13
23-36
38-50
61-74
Moisture 100-105° C %
1.87
1.72
1.66
2.55
1
2
2
2
200M - 2mm
% -
B21
50/LA - 200M
%
50
52
45
50
20M
-
50M
%
15
14
18
13
2M
-
20M
%
13
13
13
6
<2M
%
18
17
21
28
nd
nd
nd
nd
;
CaCOg Equivalent %
4.1
3.5
3.6
Loss on Ignition %
4.7
Organic Carbon %
1.2
nd
nd
nd
Total Nitrogen %
0.12
nd
nd
nd
ao
nd
nd
nd
C/N Ratio
pH in water (1:2.5)
4.1
4.5
4.7
4.7
pH in M/100 CaCl2
3.6
3.7
3.9
4.0
Exchangeable Calcium meq %
0.5
0.5
0.3
0.3
Exchangeable Magnesium meq %
0.15
0.14
0.18
0.23
Exchangeable Potassium meq %
0.47
0.13
0.10
0.12
Exchangeable Sodium meq %
0.08
0.10
0.10
0.10
Total Exchangeable Bases meq %
1.2
0.9
0.7
0.8
Exchangeable Hydrogen meq %
8.6
6.9
5.5
5.0
Cation Exchange Capacity meq %
(by addition)
9.8
7.8
6.2
5.8
12
Base Saturation %
nd = no determination or no sample;
(80714)
61
12
tr = trace; - = nil
11
14
PROFILE S
CLAYPAN SOIL INTERGRADE
LOCATION:
800 m (% mile) from Tsoinyane River, near Mohobong
track, Leribe district.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Towards the foot of a broad convex slope of about 3°.
A slightly accumulating position.
PARENT MATERIAL:
Developed from colluvial drift over Molteno Sandstone.
LAND USE:
Rough grass, cultivated land.
SOIL DRAINAGE:
Free, permeability moderately slow.
i
HORIZON
DEPTH cm (in)
DESCRIPTION
Ap
0 - 8 (0 - 3)
Dark brown, 10 YR 3/3, moist; fine sandy
clay loam; weak to moderate fine blocky
structure; friable to firm consistence,
moist; smooth, clear boundary to:
B2
8 - 33 (3 - 13)
dark yellowish brown, 10 YR 3/4, moist; fine
sandy clay; moderate medium blocky structure;
firm consistence, moist; sticky, plastic consistence, wet; smooth, diffuse boundary to:
33 - 125 (13 - 49)
dark yellowish brown, 10 YR 4/4, moist, tending to dark brown or dark greyish brown; fine
sandy clay; structureless; firm consistence,
moist.
(80714)
62
PROFILE S
C
HORIZON
Ap
DEPTH cm
0-8
21-33
51-64
Moisture 100-105° C %
3.91
7.28
7.42
%
4
2
3
2 0 0 M - 2mm
B2
50M
- 200M
%
44
36
39
20M
-
50M
%
11
10
9
2M
-
20M
%
10
13
18
<2M
%
27
33
26
nd
nd
-
CaCOg Equivalent %
9.6
7.9
Loss on Ignition %
7.1
Organic Carbon %
1.3
nd
nd
Total Nitrogen %
0.14
nd
nd
,9
nd
nd
C/N Ratio
pH in water (1: 2. 5)
5.7
6.3
6.7
PH
4.9
5.5
5.9
11.1
17.8
21.6
in M/100 CaCl2
Exchangeable Calcium meq %
11
13
0.50
0.31
0.26
0.14
0.23
0.41
Exchangeable Magnesium meq %
8.1
Exchangeable Potassium meq %
Exchangeable Sodium meq %
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
Base Saturation %
19.8
29.3
35.3
6.2
6.1
4.4
26.0
35.4
39.7
76
nd = no determination or no sample;
(80714)
63
83
tr = trace; - = nil
89
PROFILE T
CALCIMORPHIC SOIL
INTERGRADE
LOCATION:
By Fusi Village, Mountain Road, about 2,070 m (6,900 feet)
elevation.
CLIMATE:
About 760-875 mm (30-35 in) annual rainfall.
SITE:
Northern aspect, on a broad, straight slope about 12°.
PARENT MATERIAL
Developed from weathering basaltic rocks.
VEGETATION:
Poor Themeda veld.
SOIL DRAINAGE:
Free, permeability moderate.
HORIZON
DEPTH cm (in)
DESCRIPTION
All
0 - 15 (0 - 6)
Dark brown, 10 YR 3/3, moist; loamy sand;
structureless; loose consistence, dry; smooth,
clear boundary to:
A12
15 - 35 (6 - 14)
dark reddish brown, 5 YR 3/4, moist; clay loam;
strong medium sub-angular blocky (breaking to
granular) structure; firm consistence, moist;
slightly sticky, slightly plastic consistence,
wet; smooth, clear boundary to:
C
3 5 - 7 0 (14 - 28) reddish brown, 5 YR 4/4, moist; sandy loam;
much weathering basaltic material; weak coarse
blocky structure; wavy, abrupt boundary to:
R
at 70 (28)
(80714)
solid basalt lava.
64
PROFILE T
HORIZON
A12
DEPTH cm
18-31
Moisture 100-105° C %
200M
- 2mm
%
7.18
5
•
%
30
- 50M
%
9
2/LA - 20/x
%
15
50/u - 2 0 0 M
20M
<2M
31
%
nd
CaCOo Equivalent %
Loss on Ignition %
13.0
Organic Carbon %
1.1
Total Nitrogen %
0.16
C/N Ratio
,7
pH in water (1:2.5)
5.7
pH in M/100 CaCl2
6.3
Exchangeable Calcium meq %
11.0
Exchangeable Magnesium meq %
20
Exchangeable Potassium meq %
0.36
Exchangeable Sodium meq %
0.06
Total Exchangeable Bases meq %
Exchangeable Hydrogen meq %
Cation Exchange Capacity meq %
(by addition)
31.4
7.4
38.8
Base Saturation %
81
nd = no determination or no sample;
(80714)
65
tr = trace;- - nil
METHODS OF ANALYSIS
Preparation of sample: the soil taken from the field is air dried and hand
ground to pass a 2 mm screen.
A sub-sample is ground in a Morrice mechanical
pestle and mortar (agate) to pass a 0.5 mm sieve.
The 2 mm sample is used
for all determinations except carbon, nitrogen and calcium carbonate
equivalent which are made on the 0.5 mm sample.
Mechanical analysis: the sample is dispersed using sodium hexa-metaphosphate
(Calgon) and sodium hypochlorite.
Calcium carbonate is not dissolved.
Coarse sand (200M - 2 mm) is retained on a suitable sieve; the fractions
<2M» 2-20/U. and 20-50/x are obtained by sedimentation analysis using an
hydrometer (Bouyoucos, 1951).
The 50-200/LA fraction is calculated by
difference, after making allowance for the organic matter present.
The
fractions separated are:
International coarse sand
200ft - 2 mm
International fine sand
f 50/i - 200^
\
[ 2 0 M - 50M "
International silt
International clay
2M - 20M
U.S. Soils
Bureau silt
<1y.
Loss on ignition: this value is determined using a muffle furnace maintained
at 850°C and is corrected for decomposition of calcium carbonate, when this
is present.
Calcium carbonate equivalent: a calcimeter (Bascomb, 1961) is used to
measure the volume of carbon dioxide evolved from the sample on treatment
with 1:3 hydrochloric acid.
This is calculated to the equivalent amount of
calcium carbonate irrespective of whether other carbonates contribute.
Organic carbon: Tinsley's procedure (Tinsley, 1950) of wet oxidation under
reflux with a mixture of 0.4N sodium dichromate, 15N sulphuric acid and 3N
phosphoric acid, at 140°C for 2 hours, is used.
The excess of dichromate is
titrated against ferrous ammonium sulphate using barium diphenylamine
sulphonate as indicator.
Total Nitrogen: a Kjeldahl digestion is followed by steam distillation of an
aliquot using a Hoskins apparatus (Hoskins, 1944) the distillate is absorbed
in boric acid and titrated with 0.01N hydrochloric acid.
pH measurements: these are made electometrically in a 1:2.5 suspension of
soil (a) in water (b) in 0.01M calcium chloride (Schofield and Taylor, 1955).
Exchangeable bases: the soil is leached with neutral normal ammonium acetate.
Sodium and potassium in the leachate are determined directly using an Eel
flame photometer, while calcium is determined in the same apparatus after the
addition of magnesium as release agent (Rowe, 1963). Magnesium is determined
spectrographically using a porous cup technique (Scott and Ure, 1958).
Exchangeable hydrogen: a modification of the method of Mados (1943) is used.
The soil is equilibrated with 0.2N ammonium hydroxide and formaldehyde is
added.
After shaking, the formaldehyde is centrifuged off, 2.5N barium
(80714)
66
chloride is added and the mixture again shaken and centrifuged.
supernatant liquid is then titrated with O.IN sodium hydroxide.
The
Soluble salts: these are determined by conductivity measurement on a 1:5
water extract.
The results are recalculated in terms of meq per 100 g soil.
(United States Department of Agriculture 1954).
(80714)
67
i
APPENDIX II - X-RAY ANALYSIS DATA
(80714)
69
00
o
-J
APPENDIX I I
X-RAY ANALYSIS
(Surface horizons)
SAMPLE
NO.
LOCALITY
SOIL TYPE
MICA
KAOLIN
VERMIOULITE MCNIMORILLONITE
FELSPAR
QUARTZ
QOETHTTE
HAEMATITE
X 983
Leribe
Red-Brown
Fersiallitic
Moderate
Dominant
-
-
Present
Much
-
Present
X 984
Berea
Yellow-Brown
Fersiallitic
Moderate
Dominant
-
-
Present
Present
-
Present
X 985
Matsieng
Red-Brown
Fersiallitic
Moderate
Dominant
-
Present
Much
-
Present
X 986
Mafeteng
Claypan
Moderate
Dominant
-
-
Present
Much
-
-
X 987
Machache
Eutrophic Brown
Dominant
Moderate
-
-
-
Present
Present
X 988
Maseru
Claypan
Moderate
Dominant
-
-
Present
Much
-
-
X 989
Mokhotlong Calcimorphic
-
Very little
Present
Present
-
Present
Very little
Dominant >75%, Moderate 26-50%, Very little 5-10%.
samples.
Dominant
Present
Present, Much, refer to non-clay minerals, percentages of which could not be determined in these
APPENDIX III - AREAS OF THE DIFFERENT
SOIL MAPPING UNITS
(80714)
71
APPENDIX III
AREAS OF THE DIFFERENT SOIL MAPPING UNITS
AREA: SQUARE AREA: SQUARE
KILOMETRES
MILES
SOIL MAPPING UNIT
1
2
3
4
Lithosols on lava
Lithosols on lava/Basalt rock debris
Lithosols on lava/Calcimorphic soils
Lithosols on rocks rich in ferromagnesian
minerals
5 Lithosols on rocks rich in ferromagnesian
minerals/Eutrophic brown soils
6 Lithosols on sedimentary rocks/Sedimentary
rock debris
7 Lithosols on sedimentary rocks/Fersiallitic
soils
8 Lithosols on sedimentary rocks/Ferrallitic
soils
9 Juvenile soils on recent riverine alluvium
10
11
Calcimorphic soils/Lithosols on lava
Calcimorphic soils/Vertisols
12
13
lithomorphic origin
lithomorphic origin/
soils
topographic depressions
Vertisols of
Vertisols of
Calcimorphic
14 Vertisols of
15 Claypan soils (Maseru set)
16 Claypan soils/Vertisols
17 Claypan soils (Maseru set/Sephula set)
18 Claypan soils/Fersiallitic soils
19 Claypan soils (Sephula set)
20 Claypan soils (Sephula set/Maseru set)
4317.51
3449.87
6570.01
166.54
1667.0
1332.0
3695.0
64.3
209.53
467.0
4314.92
1666.0
10.36
4.0
20.72
8.0
39.11
15.1
2362.07
88.06
912.0
34.0
44.03
196.84
17.0
76.0
202.02
78.0
2444.95
5.70
1.56
76.41
202.02
1.56
944.0
2.2
0.6
29.5.
78.0
0.6
21
Eutrophic brown soils/Vertisols
898.73
347.0
22
23
24
25
Fersiallitic
Fersiallitic
Fersiallitic
Fersiallitic
738.15
33.67
91.69
31.08
285.0
13.0
35.4
12.0
26
Ferrallitic soils/Lithosols
70.19
27.1
(80714)
soils
soils/Lithosols
soils/Claypan soils
- Lithosol intergrades
72
REFERENCES AND RELEVANT WORKS
AOOCKS, J.P.H.
1953
Veld types of South Africa.
S. 'Afr. Botanical Sufv. Mem. 28.
BASOOMB, C.L.
1961
A calcimeter for routine use on soil samples.
Chem. $ Ind., 45, 1826-7.
BAWDEN, M.G. and
CARROLL, D.M.
1967
The Land Resources of Lesotho
(Basutoland).
Tolworth: Land Resources Division,
Directorate of Overseas Surveys. (In the press)
ROUYOUCOS, G.J.
1951
A recalibration of the hydrometer method for
making mechanical analyses of soils.
Agron. J., 43, 434.
De VILLIERS, J.M.
1965
The genesis of some Natal soils II. Estcourt,
Avalon, Bellevue and Rensburgspruit series.
S. Afr. J. Airic. Sei., 8, 507-22.
DIXEY, F.
1942
Erosion cycles in Central and Southern
Africa.
Tr. Geol. Soc. S. Afr., 41, 113-70.
D'HOORE, J.
1964
Soil map of Africa,
scale
Explanatory monograph.
Lago s, CCTA/CSA.
Du TOIT, A.L.
1954
The Geoloiy of South Africa,
Edinburgh: Oliver and Boyd.
HOSKINS, J.L.
1944
An interchangeable micro and macro steam
distillation apparatus.
Analyst, 69, 271.
KING, L.C.
1962
Morphology of the Earth.
Edinburgh and London: Oliver and Boyd.
MADOS, L.
1943
Eine schneilmethode zur serienweisen
Bestimmung der Adsorptionsungesättigheit
von Böden.
Bodenk. u. Pfl. Ernähr, 32, 351-8.
MURDOCH, G.
1964
Soil survey and classification in
Swaziland, 1955-63.
African Soils, 9,117-35.
RATTRAY, J.M.
1960
The grass cover of Africa. FAO
Agricultural
Study 49.
RICHARDS, L.A. (ed.)
1954
Saline and Alkali Soils.
Agricultural
Handbook. 60,
United States Department of Agriculture,
Washington, U.S. Govt. Printing Office.
(80714)
73
1:5,000,000
3rd ed.,
HOWE, J.J.
1963
Releasing-addition method for the flamephotometric determination of calcium in
thermal waters.
Geochim. et Cosmochim. Acta., 27, 915,.
SCHOFIELD, R.K., and
TAYLOR, A.W.
1955
Measurements of the activities of bases in
soils.
J. Soil Sei., 6, 137.
SQOTT, R.O., and
URE, A.M.
1958
The determination of magnesium in solution
by direct photometry.
Analyst,
83, 561-70.
SOIL SURVEY STAFF,
U.S.D.A.
1951
Soil Survey Manual.
Agricultural
Handbook 18, United States.
Department of Agriculture
Washington, U.S. Govt. Printing Office.
SOIL SURVEY STAFF,
U.S.D.A.
1960
Soil classification,
a comprehensive
system,
7th
Approximation.
Soil Conservation Service
United States Department of Agriculture
Washington, U.S. Govt. Printing Office.
STAPLES, R.R., and
HUDSON, W.K.
1938
An Ecological Survey of the Mountain Area
of
Basutoland.
London: Crown Agents.
STOCKLEY, G.M.
1947
Report on the Geology of
Basutoland.
Maseru: Government Printer.
TAYLOR, N.H., and
POHLEN, I.J.
1962
Soil Survey Method.
NZ Soil Bur. Bull. 25.
TINSLEY, J.
1950
The determination of organic carbon in soils
by dichromate mixtures.
Trans. 4th Int. Congr. Soil Sei., 1, 161-4.
VAN DER MERWE, C R .
1941
Soil groups and sub-groups of South Africa.
S. Afr. Sei. Bull. 231. ,
Pretoria, Government Printer.
(80714)
74
PUBLICATIONS OF THE LAND RESOURCES DIVISION
BAWDEN, M. G. and
LANGDALE-BROWN, I.
1961
An aerial photographic reconnaissance of the present
and possible land use in the Bamenda Area, Southern
Cameroon.*
BAWDEN, M. G. and
STOBBS, A. R.
1963
The land resources of Eastern Bechuanaland.*
LANGDALE-BROWN, I. and
SPOONER, R. J.
1963
The land use prospects of Northern Bechuanaland.*
LAND RESOURCE STUDIES
SPOONER, R. J. and
JENKIN, R. N.
1967
The development of the Lower Mgeta River Area of the
United Republic of Tanzania.
Land Resource Study So. 1.
BAWDEN, M. G. and
TULEY, P.
1967
The land resources of Southern Sardauna and
Southern Adamawa Provinces, Northern Nigeria.
Land Resource Study So. 2.
BAWDEN, M. G. and
CARROLL, D. M.
1967
JENKIN, R. N. and
FOALE, M. A.
1967
The land resources of Lesotho.
Land Resource Study So. 3.
An investigation of the coconut growing potential
of Christmas Island.
Land Resource Study So. U.
TECHNICAL BULLETINS
CARROLL, D. M. and
BASCOMB, C. L.
1967
Notes on the soils of Lesotho.
Technical Bulletin
* Out of print.
D 80714/1/5892/12 600 1/67 TPD
75
So. 1.